#astronomical_research

[phonemantra-blog]

Scientists from Italy and Germany have discovered exoplanet GJ 367b, which is likely composed entirely of iron. Using the HARPS spectrograph and TESS observations, they found that more than 90% of the planet's mass is made up of its iron core. Researchers from the University of Turin in Italy and the State Star Observatory of Thuringia in Germany have made an interesting discovery: the exoplanet GJ 367b is most likely composed entirely of iron.  This makes it the densest known planet with a short orbital period. GJ 367b was first spotted in 2015 by NASA's TESS (Transiting Exoplanet Survey Satellite) space telescope and has a density 1.85 times that of Earth. [caption id="attachment_69273" align="aligncenter" width="780"] GJ 367b[/caption] Using the European Southern Observatory's HARPS spectrograph and TESS observations, scientists determined that more than 90% of the planet's mass is made up of its iron core. The origin story of GJ 367b remains a mystery, but it may have once been a rocky planet like Earth or Mars. Its two neighboring planets, orbiting further out, are also rocky, indicating that they all formed in a similar way. GJ 367b is an exoplanet consisting only of an iron core However, GJ 367b likely went through a unique series of events that led it to lose its outer rocky layers, leaving only the core. Possible explanations include collisions with another planet closer to the host star. Another possibility is that GJ 367b was intensely irradiated by its star, causing its outer layer to burn away leaving only an iron core. The outer material could turn into gas and then be dispersed into space. It is also possible that GJ 367b underwent a combination of collisions and irradiation to form the metallic planet that astronomers observe today. The question still remains: how did GJ 367b get so close to its star? It is unlikely that it formed there. Scientists believe that gravitational interactions with other planets could have caused it to move away from its original formation site. Further study of GJ 367b could provide valuable insights into the formation and evolution of rocky and short-period planets.

[phonemantra-blog]

Two giant icy planets have collided, providing astronomers with the first such collision. Astronomers captured the aftermath of the disaster - two planets destroyed each other, forming a donut-shaped cloud, red-hot. This was the first observation of the consequences of a planetary collision. The observations could shed light not only on destructive interplanetary collisions but perhaps even how they could lead to the formation of new planets. Astronomers first noticed this event in 2021 when they noticed the visible light of the star ASASSN-21qj being repeatedly obscured. It turned out that this is not the first time the star’s brightness has changed; an analysis of previous observations showed that three years before the decrease in brightness, ASASSN-21qj doubled its luminosity in the infrared spectrum. [caption id="attachment_69281" align="aligncenter" width="780"] Astronomers[/caption] This raised the question: How can a star appear brighter in one spectrum and dimmer in another? “We looked at a range of possible ideas. The one that seemed to fit all the data we had was a collision of two giant icy planets,” said study co-author Matthew Kenworthy, an astronomer at Leiden University in the Netherlands. Astronomers have seen for the first time the aftermath of the collision of two giant icy planets According to theory, these ice giants would each be the size of Neptune, which is 17 times the mass of Earth. When they collided, they practically paralyzed each other, forming a donut-shaped cloud of hot debris. The heat of this cloud, estimated at 1,300 degrees Fahrenheit, explains the increase in brightness in the infrared. Then, as the newly formed donut continued to orbit ASASSN-21qj, it passed between the star and Earth, obscuring the light for astronomers. This is an interesting explanation, but not complete. Astronomers still don't know what triggered the planetary collision. Although a planetary collision seems like the most likely possibility based on available data, it is a fairly rare occurrence. With an estimated age of about 300 million years, the star system must have been too mature for such collisions to still occur. More observations should help confirm the collision did occur, but what's even more tantalizing is that astronomers believe that new planets and moons could eventually be born from this cloud. “My prediction is that in five to ten years we will start to see additional light emission from the system reflected from the dust cloud. If that doesn’t happen, then something else happened,” Kenworthy said.

[phonemantra-blog]

Astronomers are proposing to change the names of the Large and Small Magellanic Clouds, satellites of our galaxy, due to the controversy surrounding them, to recognize the contribution of the indigenous communities that observed these “clouds” long before Ferdinand Magellan The Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC) are two astronomical objects named after Fernando Magellan, the Portuguese explorer whose crew was the first to circumnavigate the world. Magellan and his crew carried out an incredible journey and exploration, but they were also slave owners and killed indigenous people in Argentina, Guam, and the Philippines during their expeditions.  For these reasons, astronomers are asking why these two celestial objects should be named after a colonizer, slave trader, and murderer, especially since there is precedent for renaming space objects after the name has become unethical. [caption id="attachment_68117" align="aligncenter" width="780"] Astronomers[/caption] “Renaming is not a new trend in astronomy. In 2018, the International Astronomical Union renamed Hubble's Law to the Hubble-Lemaitre Law to recognize the scientific contributions of Georges Lemaitre. Renaming the LMC and MMC would also acknowledge the contributions of the indigenous communities that identified and observed them long before Magellan,” said Professor Mia de los Reyes of Amherst College, who was the first to propose changing the name of the Magellanic Clouds. Astronomers propose renaming the Magellanic Clouds to reflect indigenous history and culture Magellan was not an astronomer and was not the first to see or describe these "clouds". People in the Southern Hemisphere have observed them for tens of thousands of years, given their names, and the stories associated with them predate the records of the Magellanic Secretary. Magellan's descriptions were not even the first to reach Europe. Italian and Arab sailors reported them at least a decade before Magellan's expedition. The original name of Arrokoth, the most distant object visited by the spacecraft, was originally Ultima Thule, the name of a distant fictional land on old maps. But this name was associated with the Third Reich and was renamed. In 2020, the International Astronomical Union and NASA decided to abandon nicknames for celestial bodies associated with colonialism, racism, and other forms of discrimination. The organizations have called for scientific designations for several objects with offensive nicknames - such as the nebula NGC 2392, which was nicknamed by the colonial term "Eskimo". A group of astronomers calling for the LMC and IMC to be renamed argues that asking for neutral scientific names should not be controversial. A petition was recently created to rename the JWST telescope due to James Webb's name's ties to the US government's massacres of LGBT civilian employees in the 1950s and 1960s when James Webb was NASA administrator. This petition led to an investigation, but in this case, however, despite sports and controversies in the astronomical community, it was decided to leave the name unchanged. “Almost all the astronomers we spoke to supported the renaming; most of the opposition we received was from a small number of members of the vocal public. I received letters telling me to return to scientific research,” said Mia de los Reyes.

[phonemantra-blog]

The world's largest radio telescope observed Barnard's Star in search of signals from alien civilizations Barnard's Star is a small red dwarf star located just six light years from Earth. Despite its proximity, it was discovered only in 1916, when E.E. Barnard discovered a particularly high intrinsic velocity of this star. It was seen on Harvard Observatory photographic plates taken in the late 1800s, but as a small and faint star, it received little attention. But since then, Barnard's star has become one of the most studied red dwarfs. Barnard's Star was one of the first stars to have planets discovered. Already in the 1970s, it was announced that there were giant planets in the orbit of this star, but further observations refuted these results. Then in 2018, astronomers measured the star's radial motion, indicating the presence of an exoplanet around 3 Earths in mass around the star. However, subsequent observations refuted this discovery, indicating that the radial fluctuations seen earlier were caused by starbursts. Recent studies have confirmed that Barnard's star does not have nearby planets that could be larger than 70% of the size of Earth and potentially habitable. [caption id="attachment_62723" align="aligncenter" width="780"] FAST radio telescope[/caption] The FAST radio telescope scanned Barnard's Star in search of extraterrestrial signals This makes Barnard's star somewhat unusual since most red dwarfs have planets. For example, the star Kepler-42, similar in size and age to Barnard's star, has at least three exoplanets. So while Barnard's Star isn't a strong candidate for extraterrestrial life, a recent study has made detailed observations of the star looking for signs of an alien signal. The study used the 500-meter spherical radio telescope FAST. The Chinese telescope has an antenna design similar to the Arecibo Observatory but is significantly larger. FAST operates in the frequency range from 70 MHz to 3 GHz, making it a good tool for searching for alien life. During the study of Barnard's Star, the astronomer looked for emissions that might be noticeable if an alien civilization were sending radio messages in our direction. The team focused its search on signals coming from Barnard's hypothetical super-Earth b and took into account the Doppler effect caused by the relative motion between it and Earth. As might be expected, the study found no evidence of an alien signal. However, this study was mainly a test of the capabilities of the FAST telescope. Future studies, especially those aimed at nearby stars with confirmed planets in the habitable zone, will have a higher chance of detecting signals.

[phonemantra-blog]

Although this discovery solves the mystery of the strange behavior of just one star - J1023, astronomers will continue to study it PSR J1023 is a special type of pulsar with strange behavior. It is located approximately 4,500 light-years from Earth in the constellation Sextant and orbits another star. For a long time, the pulsar actively pulled matter from its satellite, which accumulated in the disk around the pulsar and slowly approached it. Since this process of accumulation of matter began, the pulsar began to switch between the two modes. In "high" mode it emits X-rays, ultraviolet and visible light, while in "low" mode it is less bright at these frequencies and emits more radio waves. The pulsar can stay in each mode for a few seconds or minutes and then switch. These switchings have puzzled astronomers. [caption id="attachment_51015" align="aligncenter" width="780"] Astronomers[/caption] Astronomers used 12 telescopes to study 1 pulsar “Our work was aimed at understanding the behavior of this pulsar. We used more than ten ground-based and space-based telescopes,” says Francesco Coti Zelati, co-author of the paper. Over two nights of the year, the telescopes observed the system making more than 280 switches between high and low modes. “We found that the mode switching is due to a complex interaction between a stream of high-energy particles flying away from the pulsar and matter moving towards the pulsar,” says Koti Zelati. In the low-brightness mode, matter moving towards the pulsar is ejected in a narrow stream perpendicular to the disk. Gradually, this matter is getting closer to the pulsar, and, as it approaches, it falls under the influence of radiation from the pulsating star, heating up at the same time. The system is in high brightness mode and glows brightly in x-ray, ultraviolet and visible light. And when the amount of heated matter in the disk decreases, the star returns to a low-brightness mode.