#variable stars

[klimkovsky]

Beta Lyrae - Sheliak

The small constellation of Lyra is not only very beautiful in the configuration of the stars that make up it, but also contains among them absolutely unique universal diamonds. The star Sheliak - Beta Lyrae is one of such jewels.

Translated from Arabic, Sheliak means a turtle shell (or even the turtle itself), but the same word is used to name an ancient musical instrument similar to a harp or, in fact, a Lyre, because a resonator body was made from a turtle shell, which was necessary for a more melodious sound of the strings. A musical culture on Earth was born somewhat cruelly, singing, among other things, the heavenly distances in which man saw the Worlds of his future - incomparably happier than the one in which he lived then. But man evolved, and at some point, wood began to be used more and more often for making musical instruments - Kifaras and Lyras with a wooden body sounded even better than turtle ones. But the dim star in the constellation Lyra remained called the Turtle.

What exactly this star attracted the attention of ancient astronomers is unknown now, but it was clearly not deprived of attention. It is simply that much of the scientific information from that historical period was lost. And in the 18th century it was discovered that about once a week the star slightly "winks" - fading for a short time, becoming dimmer by about two times. This could easily have been noticed in ancient times, and certainly was noticed (as astronomers of all developed countries of the ancient era noticed similar behavior of the star Algol in the constellation Perseus), but they just could not explain it.

The variability of Beta Lyrae (as well as the variability of Algol) was explained by a young amateur astronomer, John Goodricke. He had no special education, and was also deaf and dumb, but a very keen-sighted and insightful person. John's passion was observing stars, and by the age of 20 he had already examined many of them for brightness variations - simply with the naked eye, since there were no other methods at the end of the 18th century.

Only intuition can explain John Goodricke's guess that the apparent brightness of some stars most likely changes because in reality it is not one star, but two, which, rotating around the center of mass of the system, periodically obscure each other for an observer on Earth. This bold assumption was confirmed a hundred years after the death of the amazing seer.

John Goodricke died very young - at 22, succumbing to pneumonia - two years after discovering and explaining the variability of Beta Lyrae, and just four days after being elected a Fellow of the Royal Society of London.

At the turn of the 19th and 20th centuries, astronomers learned to perform detailed spectral analysis of stars and track the behavior of absorption lines in their spectrograms. In the spectra of Sheliak (Beta Lyrae) and Beta Persei (Algol), the lines behaved similarly - slightly swaying around the places assigned to them by the chemistry of the star - synchronously with the dynamics of brightness changes. This clearly indicated the presence of two luminaries in the system and their orbital motion. This was irrefutable evidence, but indirect. A century later - already in our days - a direct image of the Beta Lyrae system was obtained using the CHARA infrared interferometer. And astronomers saw with their own eyes two stars orbiting the center of mass of the system, alternately eclipsing each other.

It was also discovered that the shapes of these stars are distorted by tidal interactions and resemble oblong melons. It was even discovered that matter flows from one star to another, which changes the proportion of masses in the system and slows down the rotation, increasing the period by 19 seconds per year. At the same time, part of the matter forms an extended accretion disk around the system, which partially dissipates into interstellar space. And in addition to the exchange of mass in this system, there is a significant loss of it.

The period of brightness variation in the Beta Lyrae system is 13 days. But since eclipses occur twice during the entire period (the stars eclipse each other in turn, as if changing places), brightness minima occur approximately once a week. But they are slightly different in depth - 0.9 and 0.5 stellar magnitudes.

Nowadays, the horizons of astronomy have expanded somewhat, thanks to advanced technologies for studying the Universe. And it is already believed that Beta Lyrae is a relatively close system to us. But still, 900 light years is not that close. To see separately stars that are twice as close to each other as the Sun and Mercury is a great achievement for optical interferometry.

The distance separating the components of this system is estimated at 40 million km. Somewhere at this distance from the Sun, in the era of the famous Le Verrier, astronomers were looking for the planet Vulcan. And they found nothing. But now they see a system of two giant stars with similar orbits.

Both components of this system are quite massive — 3 and 13 times the mass of the Sun. And in luminosity — 26 thousand and 6 thousand times, respectively. It is interesting that during the existence of the system — about 20 million years — these stars seemed to have swapped roles. The one that is now massive was skinny, developed more slowly, and the neighboring star — having quickly swelled to the size of a giant — began to share matter with the smaller star. The neighbor was not modest, and took over as much as was given. And now the star that had less mass has gained it in excess. And continues to do so.

Somewhat removed from this close and amazing pair of stars, another component of the system, the so-called Beta Lyrae B, slowly drifts along a huge orbit. What we talked about before was Beta Lyrae A. But there are many more stars in this system.

Beta Lyrae B is clearly visible even in binoculars - it is a 7th magnitude star, separated from the eclipsing variable pair by 46 arc seconds (this is the apparent size of Jupiter). In a small telescope, this double star looks very nice and is an easy object for beginner astronomy enthusiasts. Now it is known that it is also a double system, though a spectral one - not divisible into components in any telescope (they are very close to each other, or maybe it just has not deserve such close attention, and some super-powerful interferometer has not yet been deployed on it).

Another star was found 64 arc seconds away from the main pair of stars, though rather faint for amateur optics - Beta Lyrae C - 13th stellar magnitude. And further away from the aforementioned luminaries, astronomers are now checking for involvement in the system of several more stars - D, E and F. Moreover, in relation to Beta Lyrae F, even convincing evidence of a gravitational connection has been found.

Once again, we started with one star and ended up with a whole star cluster. However, this situation is not uncommon in our Universe. A rare type of star in it are stars like our Sun - stable and completely alone. But maybe that is why we now have the opportunity to study the entire diversity of other cosmic luminaries.

[inkyvoids]

What’s the scariest star in the sky? If you were one of the early stargazers, you might have chosen Algol in the constellation Perseus. That is probably why early astronomers nicknamed Algol the Demon Star. Shivers! The star Algol takes its name from an Arabic word meaning the Demon’s Head or, literally the Ghoul. It represents the terrifying snaky head of the Medusa monster. Algol is a known variable star, which waxes and wanes in brightness. The early stargazers surely knew about its changing brightness. This probably led them to name the strangely behaving star in the sky for a mythological demon. There are many variable stars known throughout the heavens, but Algol might well be the most famous of them all. The Demon Star brightens and dims with clockwork regularity. It completes one cycle in 2 days, 20 hours and 49 minutes. Plus, you can view its entire cycle with your eye alone.

[spacewonder19]

A Cepheid variable © Hubble

[daily-odile]

everything is the same except Odile is the one looping

oh. heheheheh. muahahahaha. hold on *digs through my pile of disorganized sketches*

Odile loops au; a sketch compilation!!

Some old fic drabbles + associated sketches under cut (a6 secret spoilers):

hc: Since equipment carries over, as long as Odile uses her book in a fight, she can write down notes and have it carry over loops

toxic doomed yuri (for a more fleshed out fic I highly recommend The Sweetest Thing by soreimoon, it's amazing)

[annasofthe11thdimension]

These...fake covers are...WAY too fun to draw.

Anyway, here's another cover for the start of the 3rd act of my fic series 'Like a Wheel Ever Turning', since apparently I wasn't satisfied with only having one of the damn things.

If you like wanna see Odile stuck in a time loop, and Loop slowly being forced to be an actor in the drama (VERY much against their will), here's the link.

[digi-lov]

Agunimon BT17-011 Alternative Art by p!k@ru from EX-08: Legend Pack

[poorly-drawn-mdzs]

Siffrin plays Disco Elysium AU: Featuring backseat gamer Loop.

[thecannonfodder]

Why is there so many horse posts that are about isat and I have no idea where they are???

Explanations please!!!

Update:Found out!!!

[anghraine]

wind-sage replied to this post:

it is a really fun compare and contrast between Leia I am FULLY an Organa and Luke I am a Skywalker. Neither is Wrong, just important to respect the others choice with it.

Yes, I agree! Their experiences and identities wrt the family members who raised them are often framed as equivalent, but in the OT, they really do seem to relate to each of their families in very different ways.

Leia is not indifferent to her biological parents; she has a tie to Padmé through the Force that lingers with her and matters to her, and it's very upsetting for Leia to find out her natural father is Darth Vader. But the Organas are no less her parents for that. To Leia, "my father" means Bail Organa as much as it invariably means Anakin Skywalker to Luke. She is Bail and Breha's daughter and heir in every way that matters, the princess of Alderaan to her fingertips. Even her blood relationship to Luke only reinforces the close friendship that already exists between them, and would probably matter much less to her without the pre-existing relationship and accompanying Force bond.

But all suggestion in the OT is that Luke was raised as a beloved nephew with his father's and grandmother's name, not a son in the way Leia is a daughter. And it's a potentially dangerous name, at that, which only reinforces the importance in that family situation of honoring Anakin and Shmi in how Luke was brought up to think of himself. Luke's powerful consciousness of himself as Anakin's son doesn't seem just his own thing or conflict at all with how Owen and Beru talk about Luke's tie to Anakin, but rather, reflects it— they say "your father" or "his father" to refer to Anakin and are extremely aware of Luke's legacy from Anakin (and presumably Shmi).

The fostering of a relative's child within the family can often be complex in that way, even IRL, so this isn't even improbable. And given that Owen is Luke's uncle because Owen's father bought and then freed and married Luke's grandmother who died horribly later on, it's not surprising that they would have qualms about erasing the Skywalker history or that the general family dynamic might be a bit more fraught. Luke pretty emphatically does not see Beru as his mother, despite his affection for her; he refers to Padmé as Leia's "real mother" and adds "I have no memory of my mother. I never knew her"—clearly he can only mean Padmé. It seems to me that he's digging for information about Padmé because her absence represents a different kind of loss for him than it does for Leia herself.

And yeah, I could see the disparity in their experiences being something they have to navigate later on, but ultimately the only way to fully reconcile that, IMO, is for them to realize that their family dynamics and sense of legacy were fundamentally not the same and they're not going to relate to their parents the same ways.

[staticviolet]

ANDOR S02 BBY 4

[quiltofstars]

The Ghost of Cassiopeia (IC 63) being lit up by the star Navi (γ Cassiopeiae) // Timothy Straub

The star Navi, γ Cassiopeiae, is named for the American astronaut Virgil Ivan "Gus" Grissom who flew in the Gemini 3 mission and died in the onboard fire of Apollo 1. The star's name is his middle name spelled backwards.

[zhouguang66]

do you think archangel halos are like sun cycles.

newly born ones are like protostar sun, starting to become radiant and naive and bright and burning with so much passion

while more older ones may be more of like a main sequence. yk how they like are radiant in a more stable way and it’s like a beacon of light you can trust

and like at the end of the cycle or fallen/angels losing faith they have solar eclipse. like their halos are slowly losing their light to the darkness and their vision is “clouded” but it just makes it so much more magnificent and beautiful to our eyes.

do you get what i mean like what if this was in ultrakill like grrrr

id love to see this shit in a ultrakill angel oc like go off girlie(gender neutral)

[elbiotipo]

Seeing Venus 'for reference' in the list of possibly habitable exoplanets is so humbling. It's a reminder that "yes, this planet might be an analogue of Earth, or Literal Hell, so don't get too excited just yet"

[isatinformation]

added tons of sidequest variables (as well as some others) with the help of wren @onenightbreak who did a lot of the variables i was very much not looking forward to lol

if you've ever tried looking through the code for the loop convos, you'll know that there's a Lot going on, which can be pretty overwhelming at the start. wren thankfully has handled variables 54-56 though, and has documented them on the site, which is very helpful for getting to know the loop convo logic :>

[digi-lov]

Lobomon BT17-022 Alternative Art by p!k@ru from EX-08: Legend Pack 2024

[louthestarspeaker]

You guys!! Dal's captain arc in season two is literally him just learning to trust that people will watch out for him and care about him and the institutions that are supposed to keep him safe and his crew safe and actually have his best interest at heart, I'm not the only one who thinks this right?? <- girl who thought too hard about Dal R'El and now needs to write an essay and maybe cry a little about him