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spacenutspod · 1 year ago

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About 40,000 light-years away, a rapidly spinning object has a companion that’s confounding astronomers. It’s heavier than the heaviest neutron stars, yet at the same time, it’s lighter than the lightest black holes. Measurements place it in the so-called black hole mass gap, an observed gap in the stellar population between two to five solar masses. There appear to be no neutron stars larger than two solar masses and no black holes smaller than five solar masses. Astronomers working in the Transients and Pulsars with MeerKAT (TRAPUM) collaboration found the object named PSR J0514-4002E in a globular cluster named NGC 1851. It’s an “eccentric binary millisecond pulsar,” according to the authors of a new research article in Science. The total mass of the pulsar’s companion object is 3.887 ± 0.004 solar masses, placing it right in the black hole mass gap. What is it? The new research article is titled “A Pulsar in a Binary with a Compact Object in the Mass Gap Between Neutron Stars and Black Holes.” The lead author is Ewan Barr from the Max Planck Institute for Radio Astronomy. It’s published in the journal Science. Barr and his colleagues found the object orbiting a rapidly spinning millisecond pulsar. A pulsar is a rotating neutron star resulting from a supernova explosion. Pulsars emit beams of electromagnetic energy from their poles as they spin. If the orientation between Earth and the pulsar is right, we see the pulsar’s flashes. That’s why they’re referred to as cosmic lighthouses. A millisecond pulsar has a rotational period between 1 and 10 milliseconds. That means it revolves from 60,000 to 6,000 times per minute. Pulsars are fast-spinning neutron stars that emit narrow, sweeping beams of radio waves. NASA’s Goddard Space Flight Center Pulsars are powerful tools because of their rapid and predictable spinning. The pulsar timing technique measures the pulses with precision, and any changes are noted. Those changes indicate the presence of another body, its mass, and its distance from the pulsar. “Think of it like being able to drop an almost perfect stopwatch into orbit around a star almost 40,000 light years away and then being able to time those orbits with microsecond precision,” said lead author Barr. In this research, the astronomers used the pulsar’s timing to detect the object in binary relationship with it. But it couldn’t tell them what it is. Could it be a binary system containing a pulsar and a black hole? Or could it be a pulsar and a neutron star? Could it be something else? Astronomers have never found a system containing a pulsar and a black hole, but they’d really like to. These pairings present a new way to study black holes and could also serve as a new test for Einstein’s general relativity. It the companion isn’t a small black hole but instead is a heavy neutron star, that’s scientifically valuable for a different reason. “Either possibility for the nature of the companion is exciting,” said Ben Stappers, Professor of Astrophysics at Manchester University and one of the co-authors. “A pulsar–black hole system will be an important target for testing theories of gravity, and a heavy neutron star will provide new insights in nuclear physics at very high densities.” Neutron stars are extremely dense compact objects that remain after a massive star collapses and explodes as a supernova. Neutron stars can collapse even further if they gain mass by interacting with another stellar object. But astrophysicists don’t know what these neutron stars become after they collapse. They could become black holes. This artist’s impression shows a neutron star and a companion. Neutron stars can acquire mass from companions that get too close. If they gather enough mass, they collapse even further. Image Credit: ESO/L. Calçada This is where the black hole mass gap comes into play. Scientists think that for a neutron star to collapse, it needs to have about 2.2 times the mass of the Sun. That’s the threshold needed for a collapse to occur. But theory and observation both show that these collapsed neutron stars could create black holes that are five times more massive than the Sun. This gives rise to the black hole mass gap. Astrophysicists are uncertain about the nature of objects that lie in the mass gap. There’s something there, as these observations show, but the nature of the object is difficult to discern. Whatever the companion is, the authors think it resulted from a merger of two neutron stars. “We propose that the companion formed in a merger between two earlier NSs,” they write. If the companion is a massive neutron star, then it could be a pulsar. But the authors couldn’t detect any pulsations. “We searched for radio pulsations from the companion, assuming the full allowed range of mass ratios, but did not detect any,” they explain. The binary object’s origins could explain what the object is, and astrophysicists have detailed models of binary evolution. Those models indicate that mass transfer was involved somehow. “The combination of the location in a dense globular cluster (where stellar exchange encounters often occur), the highly eccentric orbit, the fast spin of the pulsar and the large companion massindicates that the PSR J0514?4002E system is the product of a secondary exchange encounter,” the researchers explain in their article. The binary object is in NGC 1851, a densely-packed globular cluster about 40,000 light-years away. By NASA Hubble Space Telescope – Caldwell 73, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=97660597 The authors think that an earlier companion object of lower mass transferred mass to the pulsar. Those types of interactions are more likely in a globular cluster like the one the binary object is located in, where stars are tightly packed. The pulsar also rotates very rapidly, another indication that it gained mass from a companion. If this was the case, then, somehow, the current companion object replaced the previous companion. “However, a more complicated evolution with multiple exchange encounters is also possible,” the researchers explain. “We, therefore, cannot infer the nature of the companion from binary evolution models.” For now, the nature of the object is up in the air. “We, therefore, cannot determine whether the companion is a massive NS or a low-mass BH,” the authors write. But they might one day. “We’re not done with this system yet,” said co-author Arunima Dutta from MPIA. “Uncovering the true nature of the companion will be a turning point in our understanding of neutron stars, black holes, and whatever else might be lurking in the black hole mass gap.” The post Is this the Lightest Black Hole or Heaviest Neutron Star? appeared first on Universe Today.

#space #astronomy #news #science

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incorrect-quotes-from-she-ra · 4 years ago

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Actually ok i think I have a rant somewhere around here. Lemmie tell you about Neutron Stars. So Neutron Stars are the 3rd most dense object in the universe, just behind black holes and my mother. They are formed when stars go supernova, but aren't quite big enough to make a black hole. Now, Neutron Stars are insane. They are extremely bright, extremely radioactive, and extremely dense. In fact, Neutron Stars aren't supported by fusion, it's all magnetism. They are made of neutrons, which are constantly pushing eachother apart, preventing the star from collapsing into a black hole. This is in contrast to my mother, where the only thing preventing her from collapsing is spite. But, near the core, theoretically it gets dense enough for the neutrons to melt together. Creating strange matter, wjich could maybe end all life on earth, but that's a whole other thing.

Let's talk more about their insane levels of magnetism. That's right, Neutron Stars have the most powerful magnetic fields in the universe. Barely beating my mothers attraction to bad friends. But there's a type of neutron star that is on a whole other level. Magnetars are 1000 times more magnetic than regular Neutron Stars. They'll rip the iron out of your blood. They'll fuck up your TV from thousands of miles away. But that's not the only subtype of neutron stars, there's also Pulsars. Now, they're names that bc of the signals they give of, in pulses. Why? Bc of their spinning. Pulsars spin so ridiculously fast that if they were any faster they'd fall apart. The fastest of which, spins at 300 miles per hour! It's so fast its not even a sphere! And did I mention they also shoot lazers of radiation out if they're poles? This is about as much radiation as the amount of toxicity my mother releases after a bad day.

Rant/Excuse to shit on my mom over. Sincerely, ya gal.

hello!

asjhdgjcdf im so very interested in space i love it so MUCH i am the biggest space nerd jskhdfksfjd. neutron stars sound vaguely intimidating, but not as much as magnetars. i didnt know a lot of this information, thank you for sharing!!!

(pulars shoot out LASERS OF RADIATION WHERE CAN I GET ONE AKHGSDJCK)

im so sorry your mom isnt being v nice, that's very shitty :/ i find screaming into ur pillow or the sky helps. or talking to someone, which you just did!

(but seriously, babe, take care of urself, okay? youve secretly become one of my favourite anons. drink water. stretch a bit, meditate, that helps me chillax a lot. i hope things get better soon!)

#asks #leo answers stuff #anon ily #remember that things will get better soon #as cliche that is!!!

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universe-in-the-void-in-the-cube · 4 years ago

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Deep Space Astrology (Part 1)

For anyone into Deep Space Astrology this and the next part are for you. Through a few years of research on my part and reading description after description of things in space. I came up with a currently complete (very subject to additions) list of deep space objects one can use in their astrology charts.

Mind you this is a list of type of objects not the various objects themselves and the keywords I believe fit the object if they were human aka these objects have traits reminiscent to human and cultural traits. And they are not full description since these are types of objects and not the individual objects themselves.

So the best way to use these deep space objects is to see them as parts of one’s personality or culture’s personality. Therein where a deep space object is placed in the chart will add what happens or how one reacts (signs) and where in one’s life it happens (houses).

STARS

Formation

· Molecular Cloud/Stelar Nursery

o Keyword: New Ideas

· Bok Globule

o Keyword: Hidden Ideas

· Herbeg-Haro Object (HHO)

o Keyword: Wild Ideas

· Herbeg Ae/Be Star (HAeBe)

o Keyword: Puberty

· Orion Variable

o Keyword: Immature Outburst

· T Tauri Star

o Keyword: Preteen/Tween Tantrum

· FU Orionis

o Keyword: Extremes

· Pre-Main Sequence Star

o Keyword: Teenaged Years

· Young Stellar Object (YSO)

o Keyword: Childhood

· Interstellar Dust Cloud

o Keyword: Attraction

Evolution

· Red Clump

o Keyword: Mid-life Crisis

· Asymptotic Giant Branch

o Keyword: Positive Life

· Super-AGB Star

o Keyword: Old Living Young

· Blue Loop

o Keyword: Fast Life

· PG 1159 Star

o Keyword: Shocking End

· Luminous Blue Variable

o Keyword: Showoff/Attention Seeking

· Blue Straggler

o Keyword: Bright/Attention Getting Ideas

· Hypernova

o Keyword: Fad/Latest Interest

· Supernova Imposter

o Keyword: Old Idea Made New

· Kilonova

o Keyword: Newest Interest/Newest Fad

· Instability Strip

o Keyword: Time

· Unnova

o Keyword: Shadow/What You Repress

Star Systems

· Binary

o Keyword: Doubled/Two

· Connected Binary

o Keyword: Conjoined/Blend Together

· Common Envelope (CE) Binary

o Keywords: Protecting

· Symbiotic Binary

o Keywords: Cooperation

· Open Cluster

o Keyword: Acquaintances (Close Acquaintances), Loose

· Super Star Cluster

o Keyword: Education

· Planetary System

o Keyword: Home

· Multiple Stars

o Keyword: Group

· Eclipsing Binary

o Keyword: Taking Turns, Going Back and Forth

· Cluster

o Keyword: Small Groups

· Globular Cluster

o Keyword: Distant Family, Focused

· Diffuse/Reflection Nebula

o Keyword: Spread Out/Reflect Upon

· Dark/Absorption Nebula

o Keyword: Hide

· Emission Nebula

o Keyword: Shine

· Planetary Nebula

o Keyword: Swan Song

· Protostar Nebula

o Keyword: Conception

Remnants

· Helium Planet (White Dwarf)

o Keyword: Maturity

· Radio-Quiet (Neutron Star)

o Keyword: Honesty

· Binary Pulsar

o Keyword: Additional Information

· X-Ray Binary

o Keyword: Information from Multiple Sources

· Burster (X-Ray Binary)

o Keyword: Urgent/Braking NEWS/Information

· Supernova Remanent

o Keyword: Sudden Transitions

Stellar Nucleosynthesis

· Nova

o Keyword: Newness

· Symbiotic Nova

o Keyword: Shard New Ideas

· Remnant Nova

o Keyword: Integrated Ideas

· Luminous Red Nova

o Keyword: Combining Things to Make Something New

Spectral Classes

· (Violet)

o Keyword: The Unconscious Mind

· OB (Indigo)

o Keyword: The Subconscious Mind

· B (Blue)

o Keyword: The Conscious Mind

· A (White)

o Keyword: Emotions

· F (Yellow-White)

o Keyword: External Self

· G (Yellow)

o Keyword: Internal Self

· K (Orange)

o Keyword: Basic Instinct/Gut feelings

· M (Red)

o Keyword: Primal Instinct/Survival Instinct

· Wolf-Rayet Star

o Keyword: Sudden and Spectacular Things

· B[e] Star

o Keyword: Hidden Thoughts

· Subdwarf

o Keyword: Small/Minor

· O Subdwarf

o Keyword: Small, But Extremely Noticeable

· B Subdwarf

o Keyword: Small, but Noticeable

· Late Type Star (G7, G8, G9, K and M/Yellow, Orange and Red)

o Keyword: Acceptance

· Chemically Particular Star

o Keyword: Strength

· AM Star/Metallic Line Star

o Keyword: Inner Strength

· Ap/Bp Stars

o Keyword: Overabundance

· Rapidly Oscillating AP Stars

o Keyword: Sudden Change of Heart/Mind

· Barium Star (G to K Giants)

o Keyword: Trade

· Carbon Star

o Keyword: Bad Habits

· CH Stars

o Keyword: Deadly/Bad Choices

· CN Stars

o Keyword: Balance/Simplicity

· Extreme Helium Star/PV Telescopic Variable

o Keyword: Uncaring

· Lambda Boötis Star

o Keyword: Taking What You Like

· Lead Star

o Keyword: Heaviness

· Mercury-Manganese Star (B8, B9, or A0)

o Keyword: Energetic

· S Type Star

o Keyword: Relaxation

· Technetium Star/ Tc-Rich Star

o Keyword: Deadly/Dangerous

· Shell Star

o Keyword: Cover/Hiding/Protection

· Slash Star

o Keyword: Insanity/Sudden Celebrity/Negative Attention

· Brown Dwarf

o Keyword: Unrealized Potential

· Red Dwarf

o Keyword: A Slow Burn

· White Dwarf

o Keyword: Old Age

· Red Giant

o Keyword: Midlife

· Red Supergiant

o Keyword: Retirement

· Blue Supergiant

o Keyword: Life Fast Die Young

Hypothetical

· Blitzar

o Keyword: Quickness

· Magnetospheric Eternally Collapsing Object (MECO)

o Keyword: Unlimited Boarders/No Boarders

· Thorne-Żytkow Object (TZO)

o Keyword: Undeath, Vampires, Zombies, Afterlife, Paranormal, Supernatural, Ghosts, Hidden Truths.

· Quark Star

o Keyword: One’s Shadow and Integrating the Shadow

· Strange Star (Fast Radio Bursts)

o Keyword: Paranormal, Strange Happenings

· Green Star

o Sharp, Sudden Justice/Karma/Illusions

· ORC (Odd Radio Circle)

o Keyword: Strange and the Unexplained

Star Death

· Black Holes

o Keyword: Transformation

· Stellar Mass Black Hole

o Keyword: Personal Transformation

· Intermediate Mass Black Hole

o Keyword: Local/Family Transformation

· Supermassive Black Hole

o Keyword: National Transformation

· Ultramassive Black Hole

o Keyword: World Transformation

· Neutron Star

o Keyword: Private/Personal Information

· Pulsars

o Keyword: Public Information

· Quasars (White Holes)

o Keyword: Manifestation

· Masers

o Keyword: Energy

· Magnetars (Soft Gamma Ray Repeaters)

o Keyword: Awakening

#astrology #deep space astrology #stars in astrology

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nasa · 6 years ago

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5 of Your Fermi Gamma-ray Space Telescope Questions Answered

The Fermi Gamma-ray Space Telescope is a satellite in low-Earth orbit that detects gamma rays from exotic objects like black holes, neutron stars and fast-moving jets of hot gas. For 11 years Fermi has seen some of the highest-energy bursts of light in the universe and is helping scientists understand where gamma rays come from.

Confused? Don’t be! We get a ton of questions about Fermi and figured we'd take a moment to answer a few of them here.

1. Who was this Fermi guy?

The Fermi telescope was named after Enrico Fermi in recognition of his work on how the tiny particles in space become accelerated by cosmic objects, which is crucial to understanding many of the objects that his namesake satellite studies.

Enrico Fermi was an Italian physicist and Nobel Prize winner (in 1938) who immigrated to the United States to be a professor of physics at Columbia University, later moving to the University of Chicago.

Original image courtesy Argonne National Laboratory

Over the course of his career, Fermi was involved in many scientific endeavors, including the Manhattan Project, quantum theory and nuclear and particle physics. He even engineered the first-ever atomic reactor in an abandoned squash court (squash is the older, English kind of racquetball) at the University of Chicago.

There are a number of other things named after Fermi, too: Fermilab, the Enrico Fermi Nuclear Generating Station, the Enrico Fermi Institute and more. (He’s kind of a big deal in the physics world.)

Fermi even had something to say about aliens! One day at lunch with his buddies, he wondered if extraterrestrial life existed outside our solar system, and if it did, why haven't we seen it yet? His short conversation with friends sparked decades of research into this idea and has become known as the Fermi Paradox — given the vastness of the universe, there is a high probability that alien civilizations exist out there, so they should have visited us by now.

2. So, does the Fermi telescope look for extraterrestrial life?

No. Although both are named after Enrico Fermi, the Fermi telescope and the Fermi Paradox have nothing to do with one another.

Fermi does not look for aliens, extraterrestrial life or anything of the sort! If aliens were to come our way, Fermi would be no help in identifying them, and they might just slip right under Fermi’s nose. Unless, of course, those alien spacecraft were powered by processes that left behind traces of gamma rays.

Fermi detects gamma rays, the highest-energy form of light, which are often produced by events so far away the light can take billions of years to reach Earth. The satellite sees pulsars, active galaxies powered by supermassive black holes and the remnants of exploding stars. These are not your everyday stars, but the heavyweights of the universe.

3. Does the telescope shoot gamma rays?

No. Fermi DETECTS gamma rays using its two instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM).

The LAT sees about one-fifth of the sky at a time and records gamma rays that are millions of times more energetic than visible light. The GBM detects lower-energy emissions, which has helped it identify more than 2,000 gamma-ray bursts – energetic explosions in galaxies extremely far away.

The highest-energy gamma ray from a gamma-ray burst was detected by Fermi’s LAT, and traveled 3.8 billion light-years to reach us from the constellation Leo.

4. Will gamma rays turn me into a superhero?

Nope. In movies and comic books, the hero has a tragic backstory and a brush with death, only to rise out of some radioactive accident stronger and more powerful than before. In reality, that much radiation would be lethal.

In fact, as a form of radiation, gamma rays are dangerous for living cells. If you were hit with a huge amount of gamma radiation, it could be deadly — it certainly wouldn’t be the beginning of your superhero career.

5. That sounds bad…does that mean if a gamma-ray burst hit Earth, it would wipe out the planet and destroy us all?

Thankfully, our lovely planet has an amazing protector from gamma radiation: an atmosphere. That is why the Fermi telescope is in orbit; it’s easier to detect gamma rays in space!

Gamma-ray bursts are so far away that they pose no threat to Earth. Fermi sees gamma-ray bursts because the flash of gamma rays they release briefly outshines their entire home galaxies, and can sometimes outshine everything in the gamma-ray sky.

If a habitable planet were too close to one of these explosions, it is possible that the jet emerging from the explosion could wipe out all life on that planet. However, the probability is extremely low that a gamma-ray burst would happen close enough to Earth to cause harm. These events tend to occur in very distant galaxies, so we’re well out of reach.

We hope that this has helped to clear up a few misconceptions about the Fermi Gamma-ray Space Telescope. It’s a fantastic satellite, studying the craziest extragalactic events and looking for clues to unravel the mysteries of our universe!

Now that you know the basics, you probably want to learn more! Follow the Fermi Gamma-ray Space Telescope on Twitter (@NASAFermi) or Facebook (@nasafermi), and check out more awesome stuff on our Fermi webpage.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

#NASA #space #fermi #fermi paradox #discoveries #science #gamma ray #telescope #Black Hole #star #beam #light #pulsar #universe #explosion

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sciencespies · 4 years ago

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This fast radio burst repeats in a strict pattern, and we still can't figure out why

https://sciencespies.com/space/this-fast-radio-burst-repeats-in-a-strict-pattern-and-we-still-cant-figure-out-why/

This fast radio burst repeats in a strict pattern, and we still can't figure out why

After taking new radio observations, astronomers have ruled out a leading explanation for the cyclic nature of a particularly curious repeating space signal.

The signal in question is FRB 20180916B, which repeats with a 16.35-day periodicity. According to existing models, this could result from interactions between closely orbiting stars; however, the new detections – which include fast radio burst (FRB) observations at the lowest frequencies yet – do not make sense for such a binary system.

“Strong stellar winds from the companion of the fast radio burst source were expected to let most blue, short-wavelength radio light escape the system. But the redder long-wavelength radio should be blocked more, or even completely,” said astrophysicist Inés Pastor-Marazuela of the University of Amsterdam and ASTRON in the Netherlands.

“Existing binary-wind models predicted the bursts should shine only in blue, or at least last much longer there. But we saw two days of bluer radio bursts, followed by three days of redder radio bursts. We rule out the original models now – something else must be going on.”

Fast radio bursts are one of the most fascinating mysteries in the cosmos. They’re extremely short bursts of very powerful short-wavelength radio waves – as in, just milliseconds in duration, and discharging as much energy as 500 million Suns in that time. Most of the FRB sources we’ve detected have only been seen once; this makes them unpredictable and hard to study.

A few FRB sources have been detected repeating, although most have done so erratically. FRB 20180916B is one of the two exceptions found repeating on a cycle, which makes it an excellent case for learning more about these mysterious events.

Last year, we also got a major lead on what could be causing FRBs – the first such signal detected coming from within the Milky Way. It was spat out by a magnetar, a type of neutron star with an insanely powerful magnetic field.

But that doesn’t mean the case is entirely solved. We don’t know why some FRBs repeat, and others don’t, for instance – and why, for the repeating FRBs, periodicity has only been detected rarely.

When FRB 20180916B was found to repeat on a cycle, one of the leading explanations was that the neutron star emitting the burst was in a binary system with a 16.35-day orbit. If this were the case, then lower-frequency, longer radio wavelengths should be altered by the charged wind of particles surrounding the binary.

Pastor-Marazuela and her colleagues used two telescopes to make simultaneous observations of the FRB – the Low Frequency Array (LOFAR) radio telescope, and the Westerbork Synthesis Radio Telescope, both headquartered in the Netherlands. When they analyzed the data, they found redder wavelengths in the LOFAR data – meaning that binary winds could not be present to block them.

Nor, for that matter, could other low-frequency absorbing or scattering mechanisms, such as dense electron clouds.

“The fact that some fast radio bursts live in clean environments, relatively unobscured by any dense electron mist in the host galaxy, is very exciting,” said astronomer Liam Connor of the University of Amsterdam and ASTRON.

“Such bare fast radio bursts will allow us to hunt down the elusive baryonic matter that remains unaccounted for in the Universe.”

So if the binary explanation is ruled out, what could be causing the periodicity? Well, it’s still not aliens, sorry.

One explanation suggested last year involves a single object, such as a rotating magnetar or pulsar. This was thought to be a poorer fit for the data than binary wind of charged particles, since those objects have a wobbling rotation that produces periodicity, and none are known to wobble that slowly.

But with the binary wind off the table, thanks to the LOFAR and Westerbork observations, a slowly wobbling magnetar is back on it. And this suggests we still have quite a bit to learn about both magnetars and FRBs.

“An isolated, slowly rotating magnetar best explains the behavior we discovered,” Pastor-Marazuela said.

“It feels a lot like being a detective – our observations have considerably narrowed down which fast radio burst models can work.”

The research has been published in Nature.

#Space

#08-2021 Science News #2021 Science News #acts of science #Earth Environment #earth science #Environment and Nature #Nature Science #News Science Spies #Our Nature #planetary science #Science #Science Channel #science documentary #Science News #Science Spies #Science Spies News #Space Physics & Nature #Space Science #Space

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tanadrin · 6 years ago

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Some planets

Description of some of the notable worlds surveyed by the Frontier vessel DSEV Soliton during its mission spinward along the Orion-Cygnus arm:

FEC 2953-CD5a: The only planetary-mass body orbiting a B-type star; possibly an abandoned superengineering project by an alien civilization. Remarkable only in that it is utterly unremarkable: the surface is extremely smooth and covered by a worldwide sea less than one meter deep, with virtually no variation in surface composition, albedo, or density of any kind. The atmosphere is entirely inert gases, mostly nitrogen and helium, with small amounts of various noble gases. No signs of life were found, and no tectonic activity.

The lack of cratering would suggest that the surface of CD5b is extremely young - Surveyor-Xenologist Kulnai has also posited some kind of alien asteroid defense mechanism, but no indication of alien technology was found on the surface or in orbit. However, Surveyor-Astronomer Harlon has also pointed out that no asteroid-mass objects orbit CD5b’s parent star except very close in, with the vast majority of orbiting mass consisting of a fine dust of minerals and ice particles, and that under such circumstances, the only possible impactors would be rare extrastellar objects. Surveyor-Planetologist Yun insists that there is no reason to think the planet is not simply a rare natural phenomenon, a remark which caused such controversy that Surveyors Tal and Uparan were forced to send Kulnai, Harlon, and Yun to their quarters and to forbid further discussion of the question except in private logs.

FEC 2968-R3He: A small, rocky world with a highly eccentric orbit, probably of extrastellar origin. A surface exploration drone indicated that beneath the shallow regolith, the planet is a single immense piece of diamond, possibly ejected from the core of a massive gas giant. On visiting the surface, Surveyor Yun sarcastically proposed to Surveyor Harlon, who surprised everyone by accepting; in consequence of the impending nuptials, the planet has been provisionally designated Harlon’s Engagement Ring.

FEC-2991-PHKc: A world with a dense atmosphere rich in hydrogen and methane. While PHKc has a diverse microbial biosphere, it also appears to be undergoing its own Great Oxygenation Event, with exposed iron deposits having recently reached a point of saturation that can no longer absorb the excess O2 generated by marine life. Oxygen blooms in the small, shallow seas trigger massive periodic fires that sweep over much of the planet, which will presumably continue until the hydrogen and methane in the atmosphere are depleted; the burning of hydrogen in particular will likely cause the seas to grow substantially, possibly creating a true planetwide ocean.

FEC-3030-59Jd II: 59Jd is a gas giant; its moon, 59Jd II, is a small, dry world kept very seismically active by the tidal stresses of its parent body. The lack of plate tectonics means that there are massive periodic energy releases that are capable of liquefying huge parts of the crust, resulting in intermittent lava seas that resurface huge portions of the landscape. When these seas form, unique extremophile organisms flourish, whose metabolism is based on unusual high-temperature chemistry; as the lava seas cool, they die off en masse, leaving behind deposits of crystalline sand, and retreat to subsurface magma pockets and isolated shield volcanoes to await the next great seismic event.

FEC-3042-373a: An almost tidally locked planet orbiting a red dwarf. The ratio of the orbital period to the revolutionary period is not quite 1, meaning that the day-night line on the surface processes slowly. 98% of the native biomass is found in this habitable zone, trapped between scorching temperatures on the day side and freezing temperatures on the night; as a consequence, almost every organism found on the planet during the survey was capable of some kind of locomotion, resulting in an entire biosphere that marches slowly across the planet, under the stormy skies where night meets day.

Of the sessile natives, most notable were the lightning-trees, adapted to draw down bursts of electricity from the clouds; their night forms withstand the freezing temperature of the nightside through a kind of hibernation; when trapped on the day side, their shoots bury themselves deep in the bedrock, waiting for the temperature to fall enough to sprout again.

FEC-3061-HJAy: The largest terrestrial planet among a veritable swarm around a massive O-type star. The ruins on the surface indicate it was once colonized by a now long-forgotten alien race, apparently obsessed with working out the complex motions and subtle perturbations of the other bodies in the system. Their entire mythology became based on this peculiar astrology, and though they were not native to this system (indeed, had no major colonies in it besides one observatory and its supporting structures), they were convinced that it was the influence of these planets and these alone that governed the courses of their lives.

FEC-3083-0C2c: A pulsar planet, formed in the aftermath of its parent star’s demise, in the manner of PSR B1257+12. 0C2c is low-mass and contains large internal voids that form a planetwide subterranean cavern system. Thus shielded from the worst of the pulsar’s scouring radiation, these caverns host an entire low-gravity radiotrophic biosphere, including an entire sentient civilization.

After careful study of the indigenous iconography, Surveyor-Xenologist Ellana advanced the tentative hypothesis that the sentient inhabitants of 0C2c were not aware of the existence of other stars, and only partly understood the nature of space and the existence of their own star. They seem to view 0C2c as a malevolent, infernal being, from which the personification of stone and darkness, a kind of Earth-mother figure, has protected them by enclosing them in its shell. Given the difficulty of communication, it was decided by the crew that the Soliton could not make productive first contact at this time, and the matter has been delegated to a joint-species Frontier committee for further review.

FEC-3112-HJAc: A terrestrial planet shattered by a massive impact, whose surface is now split by huge crevasses. The result is a planet divided starkly between vast, airless highlands, and impossibly deep, foggy valleys into which the remaining atmosphere has drained. Each is a biosphere completely sundered from the others by millions of years of evolution--each almost as alien to the others as to another world.

FEC-3126-96A: A rogue gas giant with five Earth-sized moons. One, 96A III, hosts the frozen remains of a civilization that arose there and colonized three of the other moons as well. The builders of these ruins did not die out, but in the countless millennia since their civilization fell, and the biospheres of their worlds drastically contracted, they have evolved to fit their new environment. Their distant descendants on each moon are distinct varieties of nonsentient deep-ocean dwellers who cluster around volcanic vents fed by tidal tectonic activity

FEC-3139-9JVd: An extremely rapidly rotating planet with days only a couple of hours long; because of the high speed of rotation, the surface is wracked by blisteringly fast winds. These winds are so intense that they whip the water up into a dense surface-level fog, with no clear distinction between land, air, and sea.

FEC-3150-CCQb: In most respects, an unremarkable terrestrial planet with a rich biosphere. Notable primarily for the life cycle of its one sentient species: like Earth’s cicada, they spend the majority of their life dormant beneath the soil, emerging every decade or two in great swarms, during which they marry and reproduce and feed in a frenzy of activity that lasts only a few months. As their population and their mastery of tool use has increased, each emergence has caused more and more environmental devastation, which has induced worry among their leaders and strife among different political factions. The politics of the world are further complicated by the fact that different broods have different periods of hibernation, and were not aware of one another (unless two swarms happened to coincide) until quite recently in the planet’s history.

The tacticle-electric system of communication used by the natives proved opaque, but standard first contact greeting protocols were exchanged. The inhabitants of CCQb seemed to be aware that alien life was a possibility, but have made no attempts to travel into space themselves.

FEC-3156-AHBc: Despite being located dozens of lightyears from CCQb, the Soliton was astonished to discover that AHBc hosted a biosphere chemically identical to CCQb, with a native population that was, to all external appearance, identical to the swarmers encountered already, albeit with a dramatically different life cycle and culture. The inhabitants of AHBc professed no knowledge of CCQb, nor of any interstellar visitors before the Soliton’s arrival. There is no indication either on CCQb or AHBc that the species found there--including the sentient ones--did not evolve in situ. After considering the problem for a number of weeks, Surveyor-Geneticist Tal was observed to throw up her hands in frustration, to exclaim several blistering oaths, and to lock herself in her quarters. Efforts to coax her out are ongoing.

FEC-3171-275d: A planet notable in that intelligent life has appeared on it not once, but twice. 275d has an extremely high average surface temperature, varying between about 40C at the poles and regularly reaching 70C at the equator. The current planetary civilization, derived from arboreal stock, has conducted extensive archeological and climatological investigations of 275d’s past, and believes that a mass extinction 25 million years ago was accompanied by a massive carbon spike, the result of an industrial civilization burning fossil fuels. Whether by foolhardiness or deliberate action, they did not slow their rate of fossil fuel consumption as the planet began to warm up; several positive feedback loops subsequently triggered, accelerating the temperature increase of the surface further, and leading to the establishment of a new equilibrium where the average surface temperature was about 25C warmer. The last enclaves of the previous civilization were found at the poles, and ceased to exist at around 12 degrees of warming; as this civilization left behind no durable records of its culture, history, or beliefs, little has been ascertained as to why no effort was made to avert this warming.

The subsequent rise to sentience of the current dominant species was made possible by the great environmental shifts triggered in the process, though, although their growth has been somewhat hampered by the lack of access to readily available high-energy fuels. The Soliton made a gift of fusion and solar-powered generators to the natives before departure.

Xenologist Bulan appends this note:

It is easy for the layperson to interpret the history of alien civilizations according to the patterns of our own, to read a clear environmentalist’s moral into the fate of the first inhabitants of 275d. I caution against this. Humanity has had close contact with four alien species now, and made passing first contact with over a dozen, and the one constant is that--even among civilizations closely aligned in values with our own--the alien mind is nonetheless alien, and often driven by motivations and goals which are absurd, self-defeating, or opaque to us. It is by no means safe to assume 275d owes its present condition to arrogance, stubborness, or foolishness: these human vices are predicated on having a humanlike mind. It is not conceivable that a civilization able to induce climate change of the scale we have seen we not understand the cause of such climate change. It is entirely plausible--indeed it seems to me likely--that the architects of 275d’s warming saw it (and their own subsequent extinction) as in some sense a necessary, valuable, or important outcome on its own. Why? Neither we nor 275d’s current inhabitants can know.

#tanadrin's fiction

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theblogsofscience-blog · 5 years ago

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Pulsars - The Blogs Of Science

The Blogs Of Science

Introduction

Hi there! Evan here, The writer of TBoS blogs, today you’re going to be reading about Pulsars, these are fascinating objects in space, continue reading to know more!

What are Pulsars?

Pulsars are neutron stars rotating at mind-boggling speeds, ranging from 7 to 40 thousand rotations in a MINUTE. Due to these incredible speeds of rotation, very powerful and unstable electromagnetic fields are produced which emerge from the poles of it, this is not the only things that are coming out of its poles though, there are massive amounts of radiation and rays spewing out of here too, including gamma rays, which can literally disintegrate object because of its high energy. Moreover, a Pulsar is an extremely dangerous variant of neutron stars.

How are they formed?

When stars which are extremely large, more than 8 solar masses heavy, explode in an amazing show of fireworks known as a Supernova, it can either change into a Neutron star or a Black hole depending on its mass, if it turns into a Neutron star and if the Neutron star has a extremely fast rotational speed, it can be classified as a pulsar as a fast rotational forms strong electromagnetic fields and in turn changes the neutron star into a Pulsar.

How do we find them?

These pulsars shine very brightly and their poles appear to pulsate from where radiation is being shot into space is bright thus when pulsars spins, it gives the impression of a light blinking to the viewer, like a lighthouse.

The first Pulsar we ever found was discovered by Jocelyn Bell in 1967, at the time no one had any idea what the radio pulses meant (Pulsars give out all kinds of radiation, remember, radio, gamma, microwave, everything,) which they detected, it was name "LGM" standing for "Little Green Men" signalling towards Extra-terrestrial life, soon after Thomas Gold showed that only a spinning neutron star could create such signals.

Summary

Moreover, Pulsars are fast rotating neutron stars shooting out all kinds of radiation from their poles due to strong, VERY strong electromagnetic fields. Thus, beautiful, bright pulsating objects against the unending black canvas of space. Here’s a computer rendition (Rendered by a computer, not a real picture) by NASA!

The white orb is the neutron star, the blue bands make up the electromagnetic field (We can’t see radiation, remember, just a computer made image) and the purplish particles are the representation of radiation coming out.

Stay tuned for more posts and stay safe!

#science #astronomy

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asfeedin · 5 years ago

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Two stars with an odd wobble are stretching space and time around them

By Leah Crane

A pulsar with bright beams is doing a wobbly dance around a distant white dwarf

Getty/MARK GARLICK

A pair of distant stars have a weird wobble to their orbits, which is probably caused by a strange effect predicted by Einstein’s theory of general relativity. This tumbling motion tells us that they formed in a very unusual way.

Pulsars are dense neutron stars that emit beams of light. As they spin, those beams sweep across the sky, so we only see pulsars when their beams pass over Earth. PSR J1141-6545 is one such object, and it orbits a stellar corpse called a white dwarf, which formed when a lower-mass star ran out of fuel and lost its outer layers.

Nearly 20 years of observations of this system have enabled astronomers to calculate the two stars’ orbits around one another with extreme precision. “What we have found is that the system’s orbit is tumbling in space,” says Vivek Venkatraman Krishnan at the Max Planck Institute for Radio Astronomy in Germany.

That tumbling is due to a destabilising effect called frame dragging, which is predicted in the theory of general relativity and occurs when a fast-spinning object drags space-time around it. Imagine pressing your finger down on a piece of loose fabric and then twisting – the resulting bunching is similar to the shape of space-time around the rotating white dwarf.

Measuring the stars’ wobble due to frame dragging allowed Venkatraman Krishnan and his colleagues to calculate how fast the white dwarf was spinning. They found that it is spinning faster than the pulsar, which is twirling relatively slowly at about 2.5 rotations per second.

That indicates that this system seems to have formed in an order opposite from that we would expect. Usually, the pulsar forms first, and then as the white dwarf is losing its outer layers, the pulsar sucks up that material and starts to spin faster. In this case the white dwarf formed first, so there was no dust and gas to speed the pulsar up, and it is still spinning slowly compared with others in binary systems.

While the system is unusual compared with others we have observed, “everything about it completely agrees with the predictions of general relativity,” says Venkatraman Krishnan. He says that watching other binary systems that have faster-spinning neutron stars dragging space-time around them could let us finally understand their internal structure, which is a long-standing question in astronomy.

Journal reference: Science, DOI: 10.1126/science.aax7007

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kristablogs · 5 years ago

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A lopsided pair of dead stars could reveal some of the universe’s secrets

Two dead stars, one larger than the other, will one day collide—and tell us valuable things about the universe. (Courtesy of Arecibo Observatory/University of Central Florida - William Gonzalez and Andy Torres./)

Picture a pair of collapsed stars, light-years away, locked in a "dance" of death: a final embrace that will end in their collision. In about 500 million years, astronomers anticipate this exact scenario will play out in a system known as PSR J1913+1102. Two neutron stars will crash together, sending a shudder through the universe: the fabric of space and time will ripple in the form of gravitational waves.

Most binary systems include two comparably sized neutron stars locked in a fiercely tight orbit. But PSR J1913+1102 contains a pair of mismatched neutron stars — one of them a pulsar — with masses that are 1.62 and 1.27 times the mass of the Sun. That makes it “the most asymmetric merging system reported so far,” according to a study published Wednesday in the journal Nature detailing the system and its impending collision.

This rare, lopsided star system offers a unique opportunity to solve some of the universe’s most elusive mysteries, like how fast the universe is flying apart.

All other double neutron star systems we’ve found that are set to merge have all had stars of almost exactly equal mass, says Collin Capano, a researcher at the Max Planck Institute for Gravitational Physics who was not involved in the study. “This [new] observation is going to force us to rethink some of the assumptions we’ve made about how neutron-star binaries are formed, while also raising new questions for us to answer.”

Neutron stars are the ultra-dense smashed up remnants of long-ago supernova explosions. A pulsating neutron star is named, appropriately, a pulsar. These stars spew out visible cosmic fireworks as they rotate — like the beam of a lighthouse — that are ultimately detected as pulses of light by radio telescopes back on Earth.

By recording the precise timing of the pulses, researchers like Robert Ferdman, a physicist at the University of East Anglia and lead author of the study, can even predict future pulses. “By doing that, we can actually keep track of the rotations of the neutron star which can help us use them as “clocks” in order to determine various things — like [star] masses,” Ferdman says.

An international group of scientists, led by the University of East Anglia in the United Kingdom, relied on data collected by the Arecibo Observatory in Puerto Rico as part of a large-scale survey of the galactic plane. The new study estimates that other stellar odd couples like PSR J1913+1102 are out there; more than 1 out of every 10 of the total population of neutron star mergers is asymmetric.

This finding can help us better understand past astronomical events, too. Back on August 17, 2017, we saw a watershed moment in the history of astronomy. Researchers throughout the world witnessed the cataclysmic crash of two ultra-dense neutron stars some 130 million light-years away using Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo, its Italian sister detector. Known as GW170817, the spectacular event wasn’t surprising, but the enormous amount of matter the collision released — around five times higher than expected — remained a mystery.

While the two merging objects weigh together about 2.8 times that of the Sun, the individual masses of the two neutron stars are not known. GW170817 can be explained with other scenarios, but researchers say it’s possible the unexpected ejected material was due to a merger of objects with very different masses, like the pair in this week’s Nature study. “When the gravitational effects of the more massive star rips apart the less massive one, it will cause lots more stuff to be thrown out into space,” Ferdman says.

Vicky Kalogera, an astrophysicist in the LIGO Scientific Collaboration who was not involved in this study, says the result is very exciting. Not only does the discovery “beautifully” fit with the spectacular GW170817 event, she adds, but it’s a relief that other asymmetric systems like PSR J1913+1102 are out there.

Detecting these kinds of binary systems can also help determine how fast the fabric of the universe is expanding — a much-contested number called the Hubble constant.

Pinning this number down tells us a great deal about the origin, age, evolution, and ultimately the fate of the cosmos. And yet, the two most precise ways of measuring it — looking at the light from nearby flashing stars and the oldest observable light in the universe — are at odds with each other, with a curious 8 percent discrepancy. A third independent method of calculating the Hubble constant could help bridge that divide, and Ferdman and his colleagues hope that asymmetric mergers may be key. “It could help break the deadlock,” he adds.

Neutron star collisions are also the ultimate cosmic alchemist, cooking up the heaviest elements in the universe like gold. Though astronomers and physicists have marveled at these stellar corpses for decades, the innards of neutron stars are not completely understood. Massive collisions of neutron stars, especially asymmetric ones, may allow scientists to gain important clues about the exotic matter that makes up the interiors of these extreme, dense objects.

Hard answers for all these cosmic queries will come only with more detections. In the meantime, Ferdman and his colleagues hope to use PSR J1913+1102 as a far-flung laboratory to test our understanding of gravity.

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scootoaster · 5 years ago

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A lopsided pair of dead stars could reveal some of the universe’s secrets

This rare, lopsided star system offers a unique opportunity to solve some of the universe’s most elusive mysteries, like how fast the universe is flying apart.

Detecting these kinds of binary systems can also help determine how fast the fabric of the universe is expanding — a much-contested number called the Hubble constant.

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shirlleycoyle · 5 years ago

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Scientists Witnessed a Dead Star ‘Dragging’ the Fabric of Reality

In 1918, a pair of Austrian mathematicians named Josef Lense and Hans Thirring were thinking through the implications of Albert Einstein’s recently published general theory of relativity. If the fabric of space could be warped by gravity, they realized, it meant that rapidly spinning objects might actually drag the spacetime continuum around them as they rotate.

A century later, scientists have now witnessed this effect, known as Lense-Thirring frame-dragging, happening in a dramatic star system called PSR J1141–6545, according to a study published on Thursday in Science.

“This is the first evidence of frame-dragging in a binary star system,” said lead author Vivek Venkatraman Krishnan, a physicist at the Max Planck Institute for Radio Astronomy, in an email. “These are systems where there are two stars going around each other, unlike our Sun which is solitary.”

Astronomers discovered PSR J1141–6545 in the 1990s using Parkes radio telescope in Australia, and rapidly recognized that it was a useful natural laboratory for testing general relativity. While the theory predicts that all spinning objects drag spacetime around them, frame-dragging is far more detectable around more massive bodies that are spinning incredibly fast.

The system contains a pulsar and a white dwarf, two different types of dead star. The white dwarf is rotating incredibly fast due to past interactions with its companion, while the ultra-dense pulsar acts as a sort of gigantic "cosmic clock" that scientists can use to measure the frame drag of spacetime as the white dwarf spins.

“The rotation period of our Sun is about 25 days, which is too slow to cause a measurable drag,” Venkatraman Krishnan explained. “However, stars such as black holes, neutron stars, and white dwarfs—if sufficiently massive and fast-spinning in their own right—might provide a measurable effect.”

PSR J1141-6545 is particularly unique because the white dwarf in the system formed before the pulsar, which is a reversal of the normal sequence for these binaries. The star that created the pulsar was on its deathbed about a million years ago, but before it exploded into its current super-dense form, it shed much of its outer material.

Some that star stuff was dumped onto the white dwarf, which turbocharged its spin to a period of about three minutes, as opposed to the hour-scale day of more typical white dwarfs.

Fortuitously, the white dwarf’s companion emits precisely timed pulses of light—thus, the term pulsar—which is what makes these objects useful cosmic clocks in space. Over the past 20 years, astronomers have timed pulses from PSR J1141-6545 down to a tiny fraction of a second. That enabled them to witness a gradual drift in the system’s orbital plane of 0.0004 degrees per year, which this study confirmed is due to frame-dragging generated by the dizzying spin of the white dwarf.

“The reason we could do this is that there is a pulsar in the system,” Venkatraman Krishnan said. “Pulsars have extreme rotational stability and when one of their poles faces the Earth, they send a pulse to us for every rotation. This can be used to map the orbit of the pulsar with very high precision—something that is just not possible with other stars.”

While weak frame-dragging has been observed around our own planet using extremely sensitive satellites, this exotic binary system “induces frame-dragging that is 100 million times stronger than that of the Earth,” according to Venkatraman Krishnan.

The team hopes that its observation will spark other searches for extreme frame-dragging in the universe. This hunt will be bolstered by the next generation of radio observatories, such as the MeerKAT telescope in South Africa.

“The Southern Hemisphere has the richest portion of the Galactic plane of our Milky Way galaxy,” Venkatraman Krishnan said. “This new MeerKAT telescope has opened up several avenues for finding and observing other exotic binary systems” that can help scientists “understand fundamental physics.”

Scientists Witnessed a Dead Star ‘Dragging’ the Fabric of Reality syndicated from https://triviaqaweb.wordpress.com/feed/

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myupdatesystems-blog · 8 years ago

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Solving The Andromeda Galaxy's Bright Mystery

New Post has been published on https://myupdatesystems.com/solving-the-andromeda-galaxys-bright-mystery/

Solving The Andromeda Galaxy's Bright Mystery

Our Milky Way’s closest large galactic neighbor, the spiral Andromeda galaxy, has a strange, and very well-kept secret that it has long successfully hidden from the prying eyes of curious astronomers. Andromeda features a powerful source of high-energy X-ray emission, but its identity has remained an intriguing mystery–until now. In March 2017, a team of astronomers reported in a new study that NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) mission has managed to detect the elusive object that is the culprit behind this high-energy radiation. The object, called Swift J0042.5+4112 is a possible pulsar–a newborn neutron star that is the extremely dense, city-sized corpse of a doomed massive star that has perished in a fiery, brilliant, and beautiful supernova blast. Born spinning wildly, as they emerge–much like the Phoenix Bird of Greek mythology–from the raging funeral pyre of their massive progenitor stars, pulsars are highly magnetized objects, and Swift J0042.6+4112 shows a spectrum that is very similar to known pulsars inhabiting our own Milky Way Galaxy.

This new interpretation of the identity of the mysterious object, haunting Andromeda, is based on its emission in high-energy X-rays, which NuSTAR is uniquely capable of measuring. Furthermore, Swift J0042.6+4112 is likely a binary system, in which material from a companion star gets ripped up by the vampire-like pulsar–which spews out high-energy radiation as the stolen material grows hotter, and hotter, and hotter.

“We didn’t know what it was until we looked at it with NuSTAR,” commented Dr. Mihoko Yukita in March 23, 2017, NASA Jet Propulsion Laboratory (JPL) Press Release. Dr. Yukita, who is of Johns Hopkins University in Baltimore, Maryland, is the lead author of a research paper, describing the mysterious object, that is published in the March 15, 2017, issue of The Astrophysical Journal. The JPL is in Pasadena, California.

This newly discovered possible pulsar reveals its presence as a blue dot in a NuSTAR image of the Andromeda Galaxy (M31). The color blue was chosen to represent the highest-energy X-rays. The pulsar candidate shows itself to be brighter than anything else in its host galaxy.

Neutron stars are Tokyo-sized stellar ghosts, and pulsars are rapidly and regularly whirling newborn neutron stars. Stars, like people, do not live forever. When a massive star, that is still on the hydrogen-burning main sequence of the Hertzsprung-Russell Diagram of Stellar Evolution, grows old and has finally depleted its necessary supply of thermonuclear fuel, it reaches the inevitable end of the stellar road. The imploded mess, composed of what is left of the erstwhile hydrogen-burning massive star, creates from this wreckage a very dense core–which will become the lingering neutron star. During the explosive event, the progenitor star’s outer gaseous layers collapse toward the core–the neutron star–then violently rebound outward in the terrible, fierce fireworks of a supernova tantrum. The rapidly twirling baby neutron star–the pulsar–shoots out a brilliant beam of radiation into space. This beam is frequently likened to the brilliant, sweeping beacon of a lighthouse on Earth, and it can be observed by astronomers as pulses of radio waves and other forms of radiation.

Neutron stars can travel throughout our Universe as isolated bodies, or as members of a binary system in close contact with another still-“living” main-sequence star–or even with another stellar ghost, similar to itself. Neutron stars have also been observed embedded within bright and beautifully glowing supernova remnants. Some neutron stars even serve as the stellar parents of very unfortunate planets. Pulsar planets are hostile worlds that are mercilessly showered by a constant rain of radiation flowing out from the young (and deadly) neutron star. Indeed, the first batch of exoplanets, discovered back in 1992, orbit a pulsar. Pulsars famously flicker brilliantly off and on with remarkable regularity The pulsations of these spinning objects occur because of their extremely rapid and regular rotation. Dr. Jocelyn Bell Burnell discovered the first pulsar in 1967 when she was still a graduate student at the University of Cambridge in the UK.

Stars are immense spheres of searing-hot, roiling, glaring gas. These brilliant balls of fire are pulled together very tightly by the relentless tug of their own powerful gravity. This is why the cores of stars are both extremely dense as well as extremely bright. In fact, stars are so hot that they can engage in the process of nuclear fusion–and it is this very process that lights their fires. Nuclear fusion causes the atoms of lighter elements–such as hydrogen and helium–to fuse together to form increasingly heavier and heavier atomic elements. The production of heavier atomic elements, within the cores of stars, is called stellar nucleosynthesis. Stellar nucleosynthesis starts with the fusion of hydrogen atoms. Hydrogen is both the most abundant and lightest atomic element in the Universe. The extremely hot cores of stars fuse hydrogen atoms into the second-lightest atomic element in the Universe–which is helium. Atomic elements heavier than helium are termed metals by astronomers. All of the metals were formed in the cores of seething hot stars–or, alternatively, in the supernova explosion that ends the life of a massive star. The heaviest atomic elements of all–such as gold and uranium–are fused in the supernova explosion (supernova nucleosynthesis).

Nuclear fusion churns out a large amount of energy, which is why stars are both hot and bright. This energy production results in radiation pressure that push everything out and away from the star. This pressure is powerful enough to maintain a very necessary balance because the relentless pull of gravity squeezes everything in. Radiation pressure and gravity are in a constant tug-of-war within the star. The battle continues until the star finally has managed to burn its necessary supply of nuclear fuel. At this very critical stage, gravity goes on to win the war. As a result of gravity’s victory, the star’s core implodes–and it goes supernova. This very delicate balance between gravity and radiation pressure is dependent on the mass of the star, with the most massive stars being squeezed much more tightly than their less massive skin. Because, in massive stars, the squeeze of their own gravity is so intense, their nuclear fusion reactions proceed much more quickly than in smaller stars. Massive stars live fast and die young. Less massive stars can live quietly and peacefully, for a very long time, before they finally perish.

The weird stellar corpses that are neutron stars are commonly only about 20 kilometers in diameter. However, they weigh-in at about 1.4 times that of our Sun. Indeed, one teaspoon full of neutron star material can weigh as much as a herd of buffalo. These hot, dense, and relatively small spheres have magnetic fields that are about 1,000,000 times more intense than the most powerful magnetic fields on Earth.

The collapsing iron core belonging to a doomed massive star–that is just about ready to go supernova–triggers a chaotic, violent, brilliant event. An iron core marks a massive star’s grand finale in the universal drama. This is because iron cannot serve as fuel in the process of nuclear fusion–and nuclear fusion is what has kept the erstwhile main-sequence star fluffy against the terrible squeeze of its own gravity.

Andromeda

Spiral galaxies like our large Milky Way, and the nearby Andromeda, are majestic, starlit pinwheels twirling elegantly in Space. Both our Milky Way and Andromeda are the two largest inhabitants of the Local Group of galaxies, which also hosts about 40 smaller galactic constituents. The Local Group is a few million light-years across. However, this is actually a small region when compared to immense galaxy clusters. Enormous galactic clusters can host literally hundreds of resident galaxies. Our own Local Group is situated near the outer limits of the Virgo Galaxy Cluster whose core is about 50 million light-years from us. The numerous groups of galaxies and galaxy clusters are themselves smaller denizens of the unimaginably immense web-like, heavy filaments, and slender broad expanses, that compose the Cosmic Web. For example, the so-called Great Wall is a sheet-like collection of galaxies situated approximately 200 million light-years away from us, and a similar enormous structure is named the Great Attractor. The Great Attractor is exerting a powerful gravitational pull on the entire Virgo Cluster of galaxies. We are, of course, carried away with the rest of the galactic inhabitants of the Local Group at the breathtaking speed of several hundred kilometers per second.

Right now, Andromeda is a safe 2 million light-years away from our Galaxy–but this will change. Unfortunately, gravity’s powerful grip is pulling Andromeda towards our Milky Way at about 100 kilometers per second–and the two large spirals are headed for a violent smash-up. The good news is that this fatal collision will not happen for about 4 billion years–but when it does, both our Milky Way and Andromeda will experience a sea-change, merging together to create an elliptical (football-shaped) single galaxy–replacing the duo of former elegant and lovely spirals. The new elliptical galaxy will be twice the size of the two spirals that went into its construction. The new galaxy, that will form from the wreckage, has been given the playful name of the Milkomeda Galaxy by astronomers–in honor of the duo of former spirals that will merge together to create it.

Solving The Andromeda Galaxy’s Bright Mystery

The new study uses numerous different observations of the mysterious, bright, and bewildering object dancing in Andromeda. The observations of this intriguing object were derived from various spacecraft. In 2013, NASA’s Swift satellite reported it as a high-energy source, but its classification was unknown. This is because there are numerous objects emitting low energy X-rays in that particular region.

It turned out that the lower-energy X-ray emission from the object was a source first detected back in the 1970s by NASA’s Einstein Observatory. Other spacecraft, such as the European Space Agency’s (ESA’s) XMM-Newton and NASA’s Chandra X-ray Observatory had also spotted it. However, it wasn’t until the more recent observations from NuSTAR–along with help derived from Swift satellite data–that astronomers realized that it was the same object as the probable pulsar that emits the high-energy X-ray light of Andromeda.

Astronomers have long thought that voracious black holes, which are more massive than pulsars, usually dominate the high-energy X-ray light in galaxies. As a delectable banquet of shredded stars and clouds of gas spiral down, down, down into the greedy gravitational grip of the hungry black hole–forming a bright structure surrounding it called an accretion disk–this unfortunate material gets hotter and hotter and hotter, and these extremely high temperatures emit high-energy radiation. The pulsar, which sports a lower mass than any of Andromeda’s resident black holes, is brighter at high energies than the galaxy’s entire black hole population.

Even the supermassive black hole lurking within Andromeda’s center does not possess significant high-energy X-ray emission associated with it. Therefore, it is puzzling how a solitary pulsar could be responsible for dominating Andromeda in high-energy X-ray light. Supermassive black holes are thought to lurk hungrily in the hearts of probably every large galaxy in the Universe–including our own–and they possess millions to billions of solar masses.

“NuSTAR has made us realize the general importance of pulsar systems as X-ray-emitting components of galaxies, and the possibility that the high-energy X-ray light of Andromeda is dominated by a single pulsar system only adds to this emerging picture,” Dr. Ann Hornschemeier explained in the March 23, 2017, JPL Press Release.

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sciencespies · 4 years ago

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You can finally watch the blast of a cosmic supernova with your own eyes

https://sciencespies.com/space/you-can-finally-watch-the-blast-of-a-cosmic-supernova-with-your-own-eyes/

You can finally watch the blast of a cosmic supernova with your own eyes

A ghostly “hand” reaching through the cosmos has just given us new insight into the violent deaths of massive stars.

The spectacular structure is the ejecta from a core-collapse supernova, and, by taking images of it over a 14-year span, astronomers have been able to observe as it blasts into space at around 4,000 kilometers (2,485 miles) per second.

At the very tips of the “fingers”, the supernova remnant and blast wave – named MSH 15-52 – is punching into a cloud of gas called RCW 89, generating shocks and knots in the material, and causing the expanding supernova to decelerate.

MSH 15-52 is located 17,000 light-years away from Earth, and it seems to be one of the youngest known supernova remnants in the Milky Way. Light from the stellar explosion reached Earth approximately 1,700 years ago, as the progenitor star ran out of fuel to support fusion, exploding its outer material into space, and collapsing its core.

(NASA/CXC/SAO/P.Slane, et al.)

That collapsed core turned into a type of “dead” star called a pulsar, an extremely dense object with neutrons packed so tightly that they take on some of the properties of an atomic nucleus, pulsing light from its poles as it rotates at high speed.

This rotation also helps shape the X-ray nebula of ejected stellar material expanding into space.

Exactly how fast it is expanding has been detailed in a new study, which uses images from 2004, 2008, and 2017-2018 to observe changes in RCW 89 as the supernova remnant plunges into it.

By calculating the distance traveled by these features over time, we have a better understanding of the velocity of the shock wave, and knots of ejected stellar material in MSH 15-52. You can see this in the image below.

(NASA/SAO/NCSU/Borkowski et al.)

The blast wave, located near one of the fingertips of the hand, is a feature where MSH 15-52 meets RCW 89 that is moving at a velocity of 4,000 kilometers per second, but some knots of material are moving even faster, at up to 5,000 km/s.

These knots are thought to be clumps of magnesium and neon that formed in the star, prior to supernova explosion, and they’re moving at different speeds. Even the slowest seem insanely fast, around 1,000 km/s.

Even so, these features are slowing down as they interact with the material in RCW 89. The distance from the pulsar to RCW 89 is about 75 light-years; to bridge that distance, the required mean expansion velocity of the outer edge of MSH 15-52 is 13,000 km/s.

This means, the researchers have ascertained, that the material would have passed through a relatively low-density cavity or bubble in the gas around the exploded star before encountering RCW 89. This is consistent with the core-collapse supernova model.

As the precursor star reached the end of its main-sequence lifespan, a powerful stellar wind would have blown into the space around it, stripping the star of its hydrogen, and creating a giant cavity. Then, when the star’s core finally collapsed in a supernova, the explosion ejected the remaining stellar material into this relatively empty region of space.

RCW 89 represents the wall of the cavity. When MSH 15-52 encountered this higher-density region, the collision caused a rapid deceleration.

Supernova ejecta at the higher velocity range has also been observed in the supernova remnant Cassiopeia A, located 11,000 light-years away. This is also thought to have been a core-collapse supernova, but we observed it much more recently – light from the explosion reached Earth a mere 350 years ago.

We don’t really understand the origin of the fast-moving clumps in either supernova yet, but collecting more data, and studying such explosions at different timespans, will help astronomers painstakingly piece the puzzle together.

The research has been published in The Astrophysical Journal Letters.

#Space

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sciencespies · 4 years ago

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Extreme pulsars could be spitting out way more radiation than we thought

https://sciencespies.com/space/extreme-pulsars-could-be-spitting-out-way-more-radiation-than-we-thought/

Extreme pulsars could be spitting out way more radiation than we thought

Radio pulsars could be spitting way more powerful bursts of radiation into space than we knew.

According to a new survey of the Crab pulsar some 6,500 light-years away, a type of event known as “giant radio pulses” are accompanied by an increase in X-ray emission.

This means that these events are much more energetic than we thought; it also has implications for understanding the mysterious fast radio bursts (FRBs) that flare at Earth from millions of light-years away, across intergalactic space.

Radio pulsars are strange stellar beasties. They are a type of compact object known as a neutron star – the dense, collapsed core of a massive star that has gone supernova.

Many neutron stars are unremarkable, but pulsars … well, they pulse. They spin rapidly, beaming jets of radio emission from their poles; when those jets are oriented to flash past Earth, the stars pulse, like a rapid cosmic lighthouse, on timescales as short as milliseconds.

Not all pulsars behave the same, either. Some let out giant radio pulses – extremely short, millisecond-duration pulses of radio emission that are much stronger than the dead star’s normal emissions.

The Crab pulsar, at the heart of the picturesque Crab Nebula, is a star that went supernova a little under 1,000 years ago. It’s one of the youngest pulsars we know, with a spin period of 30 times a second.

It’s also a prolific giant pulser, and the only object we know of where these giant pulses are accompanied by an increase in emission outside of radio wavelengths. When the Crab pulsar booms, its optical light increases, too.

So an international team of astronomers led by Teruaki Enoto of the RIKEN Cluster for Pioneering Research in Japan went looking for other wavelengths. From around the world, they coordinated simultaneous observations of the pulsar using radio and X-ray telescopes, to see if they could detect an increase in X-ray emission in the giant radio pulses.

After three years, they finally detected a signal strong and clear enough to confirm that the Crab pulsar was indeed discharging around 4 percent extra X-ray emission with its giant radio pulses, suggesting that we have vastly underestimated the power of this phenomenon.

“Our measurements,” Enoto said, “imply that these giant pulses are hundreds of times more energetic than previously thought.”

We don’t actually know what causes giant radio pulses, so this is very interesting information to have. That 4 percent increase is in line with the increase in optical emission, which indicates that the higher energy radiation has the same spectral energy distribution as the normal pulses, the researchers said. This places some constraints on what can be causing the star to kick off.

What the team observed, they said, is consistent with magnetic reconnection – the release of energy that results when magnetic field lines around the star snap and reconnect. This is something the Sun does all the time; the result is a solar flare.

Giant radio pulses have also been suggested as a lower-energy version of the mysterious radio signals from other galaxies, known as fast radio bursts. Like giant radio pulses, fast radio bursts are (mostly) random, and last just milliseconds – but they come from much, much farther away and are therefore way more powerful.

Last year, astronomers detected for the first time an FRB coming from our own galaxy, emitted by a magnetar – that’s a type of neutron star with a really, really strong magnetic field. There is surprisingly little crossover between pulsars and magnetars, and some astronomers believe that magnetars could evolve from pulsars.

It’s possible that there is more than one mechanism producing FRBs, so the mystery is far from solved. This new research adds another clue. Some FRBs repeat; if they were being produced by a similar mechanism to giant radio pulses, the stars would dim too rapidly for the repeating behavior we’ve observed in at least one fast radio burst source.

So, we now know that there’s some other mechanism behind at least some fast radio bursts – but we can’t entirely rule out pulsar giant radio bursts for others.

“The relationship between the two is still controversial,” Enoto said. “These findings, along with upcoming discoveries regarding fast radio bursts, will help us to understand the relationship between these phenomena.”

We don’t know about you, but we just absolutely love a deepening space mystery.

The team’s research has been published in Science.

#Space

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sciencespies · 6 years ago

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This Is Why Black Holes Must Spin At Almost The Speed Of Light

https://sciencespies.com/news/this-is-why-black-holes-must-spin-at-almost-the-speed-of-light/

This Is Why Black Holes Must Spin At Almost The Speed Of Light

Take a look out there at the Universe, and while the stars might give off the light that you’ll first notice, a deeper look shows that there’s much more out there. The brightest, most massive stars, by their very nature, have the shortest lifespans, as they burn through their fuel far more quickly than their lower-mass counterparts. Once they’ve reached their limits and can fuse elements no further, they reach the end of their lives and become stellar corpses.

An illustration of an active black hole, one that accretes matter and accelerates a portion of it outwards in two perpendicular jets. The normal matter undergoing an acceleration like this describes how quasars work extremely well. All known, well-measured black holes have enormous rotation rates, and the laws of physics all but ensure that this is mandatory.

Mark A. Garlick

But these corpses come in multiple varieties: white dwarfs for the lowest-mass (e.g., Sun-like) stars, neutron stars for the next tier up, and black holes for the most massive stars of all. While most stars themselves may spin relatively slowly, black holes rotate at nearly the speed of light. This might seem counterintuitive, but under the laws of physics, it couldn’t be any other way. Here’s why.

The Sun’s light is due to nuclear fusion, which primarily converts hydrogen into helium. When we measure the rotation rate of the Sun, we find that it’s one of the slowest rotators in the entire Solar System, taking from 25-to-33 days to make one 360-degree rotation, dependent on latitude.

NASA/Solar Dynamics Observatory

The closest analogue we have to one of those extreme objects in our own Solar System is the Sun. In another 7 billion years or so, after becoming a red giant and burning through the helium in its core, it will end its life by blowing off its outer layers while its core contracts down to a stellar remnant.

The outer layers will form a sight known as a planetary nebula, which will glow for tens of thousands of years before returning that material to the interstellar medium, where they will participate in future generations of star formation. But the inner core, largely composed of carbon and oxygen, will contract down as far as it possibly can. In the end, gravitational collapse will only be stopped by the particles ⁠— atoms, ions and electrons ⁠— that the remnant of our Sun will be made of.

When our Sun runs out of fuel, it will become a red giant, followed by a planetary nebula with a white dwarf at the center. The Cat’s Eye nebula is a visually spectacular example of this potential fate, with the intricate, layered, asymmetrical shape of this particular one suggesting a binary companion. At the center, a young white dwarf heats up as it contracts, reaching temperatures tens of thousands of Kelvin hotter than the red giant that spawned it.

NASA, ESA, HEIC, and The Hubble Heritage Team (STScI/AURA); Acknowledgment: R. Corradi (Isaac Newton Group of Telescopes, Spain) and Z. Tsvetanov (NASA)

So long as you don’t cross a critical mass threshold, those particles will be sufficient to hold the stellar remnant up against gravitational collapse, creating a degenerate state known as a white dwarf. It will have a sizable fraction of the mass of its parent star, but crammed into a tiny fraction of the volume: approximately the size of Earth.

Astronomers now know enough about stars and stellar evolution to describe what happens during this process. For a star like our Sun, approximately 60% of its mass will get expelled in the outer layers, while the remaining 40% remains in the core. For even more massive stars, up to about 7 or 8 times the mass of our Sun, the mass fraction remaining in the core is a bit less, down to a low of about 18% for the high-mass end. The brightest star in Earth’s sky, Sirius, has a white dwarf companion, visible in the Hubble image below.

Sirius A and B, a normal (Sun-like) star and a white dwarf star, as imaged by the Hubble space telescope. Even though the white dwarf is much lower in mass, its tiny, Earth-like size ensures its escape velocity is many times larger. In addition, its rotational rate will be much, much larger than the rotational speed that it had back in its heyday when it was a full-fledged star.

NASA, ESA, H. Bond (STScI), and M. Barstow (University of Leicester)

Sirius A is a little bit brighter and more massive than our Sun, and we believe that Sirius B once told a similar story, but it ran out of fuel long ago. Today, Sirius A dominates that system, with about twice the mass of our Sun, while Sirius B is only approximately equal to our Sun’s mass.

However, based on observations of the white dwarfs that happen to pulse, we’ve learned a valuable lesson. Rather than taking multiple days or even (like our Sun) approximately a month to complete a full rotation, like normal stars tend to do, white dwarfs complete a full 360° rotation in as little as an hour. This might seem bizarre, but if you’ve ever seen a figure skating routine, the same principle that explains a spinning skater who pulls their arms in explains the white dwarfs rotational speed: the law of conservation of angular momentum.

When a figure skater like Yuko Kawaguti (pictured here from 2010’s Cup of Russia) spins with her limbs far from her body, her rotational speed (as measured by angular velocity, or the number of revolutions-per-minute) is lower than when she pulls her mass close to her axis of rotation. The conservation of angular momentum ensures that as she pulls her mass closer to the central axis of rotation, her angular velocity speeds up to compensate.

deerstop / Wikimedia Commons

What happens, then, if you were to take a star like our Sun — with the mass, volume, and rotation speed of the Sun — and compressed it down into a volume the size of the Earth?

Believe it or not, if you make the assumption that angular momentum is conserved, and that both the Sun and the compressed version of the Sun we’re imagining are spheres, this is a completely solvable problem with only one possible answer. If we go conservative, and assume the entirety of the Sun rotates once every 33 days (the longest amount of time it takes any part of the Sun’s photosphere to complete one 360° rotation) and that only the inner 40% of the Sun becomes a white dwarf, you get a remarkable answer: the Sun, as a white dwarf, will complete a rotation in just 25 minutes.

When lower-mass, Sun-like stars run out of fuel, they blow off their outer layers in a planetary nebula, but the center contracts down to form a white dwarf, which takes a very long time to fade to darkness. The planetary nebula our Sun will generate should fade away completely, with only the white dwarf and our remnant planets left, after approximately 9.5 billion years. On occasion, objects will be tidally torn apart, adding dusty rings to what remains of our Solar System, but they will be transient. The white dwarf will rotate far, far faster than our Sun presently does.

Mark Garlick / University of Warwick

By bringing all of that mass close in to the stellar remnant’s axis of rotation, we ensure that its rotational speed must rise. In general, if you halve the radius that an object has as it rotates, its rotational speed increases by a factor of four. If you consider that it takes approximately 109 Earths to go across the diameter of the Sun, you can derive the same answer for yourself.

Unsurprisingly, then, you might start to ask about neutron stars or black holes: even more extreme objects. A neutron star is typically the product of a much more massive star ending its life in a supernova, where the particles in the core get so compressed that it behaves as one giant atomic nucleus composed almost exclusively (90% or more) of neutrons. Neutron stars are typically twice the mass of our Sun, but just about 20-to-40 km across. They rotate far more rapidly than any known star or white dwarf ever could.

A neutron star is one of the densest collections of matter in the Universe, but there is an upper limit to their mass. Exceed it, and the neutron star will further collapse to form a black hole. The fastest-spinning neutron star we’ve ever discovered is a pulsar that revolves 766 times per second: faster than our Sun would spin if we collapsed it down to the size of a neutron star.

ESO/Luís Calçada

If you instead did the thought experiment of compressing the entire Sun down into a volume that was 40 kilometers in diameter, you’d get a much, much more rapid rotation rate than you ever got for a white dwarf star: about 10 milliseconds. That same principle we applied to a figure skater, about the conservation of angular momentum, leads us to the conclusion that neutron stars could complete more than 100 full rotations in a single second.

In fact, this lines up perfectly with our actual observations. Some neutron stars emit radio pulses along Earth’s line-of-sight to them: pulsars. We can measure the pulse periods of these objects, and while some of them take approximately a full second to complete a rotation, some of them rotate in as little as 1.3 milliseconds, up to a maximum of 766 rotations-per-second.

A neutron star is very small and low in overall luminosity, but it’s very hot, and takes a long time to cool down. If your eyes were good enough, you’d see it shine for millions of times the present age of the Universe. Neutron stars emit light from X-rays down into the radio part of the spectrum, and some of them pulse with each rotation from our perspective, enabling us to measure their rotational periods.

ESO/L. Calçada

These millisecond pulsars are moving fast. At their surfaces, those rotation rates correspond to relativistic speeds: exceeding 50% the speed of light for the most extreme objects. But neutron stars aren’t the densest objects in the Universe; that honor goes to black holes, which take all that mass and compress it down into a region of space where even an object moving at the speed of light couldn’t escape from it.

If you compressed the Sun down into a volume just 3 kilometers in radius, that would force it to form a black hole. And yet, the conservation of angular momentum would mean that much of that internal region would experience frame-dragging so severe that space itself would get dragged at speeds approaching the speed of light, even outside of the Schwarzschild radius of the black hole. The more you compress that mass down, the faster the fabric of space itself gets dragged.

When a massive enough star ends its life, or two massive enough stellar remnants merge, a black hole can form, with an event horizon proportional to its mass and an accretion disk of infalling matter surrounding it. When the black hole rotates, the space both outside and inside the event horizon rotates, too: this is the effect of frame-dragging, which can be enormous for black holes.

ESA/Hubble, ESO, M. Kornmesser

Realistically, we can’t measure the frame-dragging of space itself. But we can measure the frame-dragging effects on matter that exist within that space, and for black holes, that means looking at the accretion disks and accretion flows around these black holes. Perhaps paradoxically, the smallest mass black holes, which have the smallest event horizons, actually have the largest amounts of spatial curvature near their horizons.

You might think, therefore, that they’d make the best laboratories for testing these frame dragging effects. But nature surprised us on that front: a supermassive black hole at the center of galaxy NGC 1365 has had the radiation emitted from the volume outside of it detected and measured, revealing its speed. Even at these large distances, the material spins at 84% the speed of light. If you insist that angular momentum be conserved, it couldn’t have turned out any other way.

While the concept of how spacetime flows outside and inside the (outer) event horizon for a rotating black hole is similar to that for a non-rotating black hole, there are some fundamental differences that lead to some incredibly different details when you consider what an observer who falls through that horizon will see of the outside (and inside) worlds. The simulations break down when you encounter the outer event horizon.

Andrew Hamilton / JILA / University of Colorado

It’s a tremendously difficult thing to intuit: the notion that black holes should spin at almost the speed of light. After all, the stars that black holes are built from rotate extremely slowly, even by Earth’s standards of one rotation every 24 hours. Yet if you remember that most of the stars in our Universe also have enormous volumes, you’ll realize that they contain an enormous amount of angular momentum.

If you compress that volume down to be very small, those objects have no choice. If angular momentum has to be conserved, all they can do is spin up their rotational speeds until they almost reach the speed of light. At that point, gravitational waves will kick in, and some of that energy (and angular momentum) gets radiated away. If not for that process, black holes might not be black after all, instead revealing naked singularities at their centers. In this Universe, black holes have no choice but to rotate at extraordinary speeds. Perhaps someday, we’ll be able to measure that directly.

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Ethan Siegel – Ph.D. astrophysicist, author, and science communicator, who professes physics and astronomy at various colleges.

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