UvA Faculty of Science’s Post

This week, three Museum astronomers presented their findings on new brown dwarf discoveries at the American Astronomical Society (AAS)'s annual meeting. First up: A team led by Museum Astrophysicist Jackie Faherty was recently awarded time with NASA’s James Webb Space Telescope (JWST) to investigate 12 cold brown dwarfs. The researchers found something surprising in the data collected from the world W1935: the emission of methane. Methane is abundant in brown dwarfs, but it is usually absorbed—not emitted. Faherty’s team plans to continue studying this world. The findings are in press for the journal Nature. Postdoctoral fellow Genaro Suárez also discussed his research on brown dwarfs, but focused on their cloudy skies. Based on data collected with the Spitzer Space Telescope, Suárez and collaborators have shown that there are more clouds near the equator of brown dwarfs than at the poles and that these clouds change the infrared color of the objects. The study was published in The Astrophysical Journal Letters in 2023. Finally, Austin Rothermich, a graduate student at the The Graduate Center, City University of New York and the Museum, announced the identification of 89 new “ultracool dwarfs.” All of them were identified as part of the Backyard Worlds citizen science project. The study, which was submitted for peer review to The Astrophysical Journal, includes 21 citizen scientists as co-authors. Read more about all of their research in our latest blog post: https://bit.ly/3vFk96S #astronomy #research #museums #space #STEM

Researchers using Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array have identified new details about the size and appearance of the North Star, also known as Polaris. Earth's North Pole points to a direction in space marked by the North Star. Polaris is both a navigation aid and a remarkable star in its own right. It is the brightest member of a triple-star system and is a pulsating variable star. Polaris gets brighter and fainter periodically as the star's diameter grows and shrinks over a four-day cycle. Polaris is a kind of star known as a Cepheid variable. Astronomers use these stars as "standard candles" because their true brightness depends on their period of pulsation: Brighter stars pulsate slower than fainter stars. How bright a star appears in the sky depends on the star's true brightness and the distance to the star. Because we know the true brightness of a Cepheid based on its pulsational period, astronomers can use them to measure the distances to their host galaxies and to infer the expansion rate of the universe. A team of astronomers led by Nancy Evans at the Center for Astrophysics | Harvard & Smithsonian observed Polaris using the CHARA optical interferometric array of six telescopes at Mount Wilson, Calif. The goal of the investigation was to map the orbit of the close, faint companion that orbits Polaris every 30 years. “The small separation and large contrast in brightness between the two stars makes it extremely challenging to resolve the binary system during their closest approach," Evans said. The CHARA Array combines the light of six telescopes that are spread across the mountaintop at the historic Mount Wilson Observatory. By combining the light, the CHARA Array acted like a 330-meter telescope to detect the faint companion as it passed close to Polaris. The observations of Polaris were recorded using the MIRC-X camera built by astronomers at the University of Michigan and Exeter University in the U.K. The MIRC-X camera has the remarkable ability to capture details of stellar surfaces. Full Article: https://lnkd.in/gEc2MRge #MIRCX #CHARA #NorthStar CHARA Array false-color image of Polaris from April 2021 that reveals large bright and dark spots on the surface. Polaris appears about 600,000 times smaller than the full moon in the sky. (Georgia State University / CHARA Array)

"Hycean planets may be able to host life even though they’re outside what scientists consider the regular habitable zone. Their thick atmospheres can trap enough heat to keep the oceans warm even though they’re not close to their stars. Astronomers have found another one of these potential hycean worlds named TOI-270 d. The word hycean is a portmanteau of ‘hydrogen’ and ‘ocean’ and it describes worlds with surface oceans and thick hydrogen-rich atmospheres. Scientists think that they may be common around red dwarfs and that they could be habitable, although any life that exists on a hycean world would be aquatic. Because they contain so much water, scientists think they’re larger than comparable non-hycean planets. Their larger size makes them easier targets for atmospheric study by the JWST. Though hycean worlds are largely hypothetical now, the JWST is heralding a new era in planetary science and may be able to show that they do exist. The telescope’s ability to characterize exoplanet atmospheres could be the key to confirming their existence. Using transmission spectroscopy, the space telescope can watch as starlight travels through their atmospheres, revealing the presence of certain important chemicals and even biosignatures. The exoplanet TOI-270 d could be a hycean world, and a new paper presents evidence supporting that. The paper is “Possible Hycean conditions in the sub-Neptune TOI-270 d,” and it’s published in the journal Astronomy and Astrophysics. The authors are Måns Holmberg and Nikku Madhusudhan, both from the Institute of Astronomy at the University of Cambridge." paper https://lnkd.in/gNPtbxBp.

"If" in the event there is a '9th planet out there' (Pluto? Anyone? Bueller?) none of our current rocket-based #propulsionsystems would ever be able to reach such a distant world or feasibly make the journey for manned #deepspace travel. The emergence of the CTPSci sciences (many are just first hearing about) brings with it the coming revelation and realization of CTP Gravitic Propulsion (https://lnkd.in/env2Rz8G) within the coming years; the 'Holy Grail' of propulsion. Future #CTPcraft (https://lnkd.in/eYycu9mT) that will utilize CTP Propulsion represents the next 'quantum leap' of human advancement and evolution #paradigm since the Wright Brothers first flight at Kitty Hawk 120 years ago. Coming advancements CTPSci sciences will offer humankind will be able to be compared much akin to 'The Expanse' (https://lnkd.in/ejmikem3) or 'Star Trek' (https://lnkd.in/eurJ2pEh) however, CTP will be 'how' such advances will occur in real life (i.e. NOT science fiction). The dawn of a new era approaches... #newbeginnings #pioneering #progress #newspaceeconomy #futurespace

Astronomers Spot Cataclysmic Collision of Giant Asteroids in Nearby Star System Nearly 20 years ago, astronomers observed a monolithic unreality of good particulate particles astir a young prima located conscionable 63 light-years distant from Earth. In caller observations from the Webb Space Telescope, however, the particulate unreality had mysteriously vanished. Now, a caller insubstantial suggests the particulate unreality whitethorn person been caused by a convulsive lawsuit that pulverized ample celestial bodies and dispersed their remains crossed the Beta Pictoris prima system. Sonos First Ever Headphones Are Too Expensive For What They Offer Using caller information from Webb, a radical of scientists spotted important changes successful the vigor signatures emitted by particulate grains recovered astir Beta Pictoris, with particles that had gone wholly missing. By comparing the Webb information to older observations captured by the Spitzer Space Telescope successful 2004 and 2005, the scientists suggest that a cataclysmic collision betwixt ample asteroids took spot astir 20 years ago, which broke isolated the celestial bodies into good particulate particles smaller than powdered sugar. The particulate apt cooled disconnected arsenic it moved distant from the star, which is wherefore it nary longer emits the aforesaid thermal features archetypal observed by Spitzer. The caller findings were presented Monday during the yearly Meeting of the American Astronomical Society successful Madison, Wisconsin. Christine Chen, an astronomer astatine the Space Telescope Science Institute and Johns Hopkins University, archetypal observed Beta Pictoris successful 2004 utilizing the Spitzer Space Telescope. The young prima strategy is location to the archetypal debris disk ever imaged astir different star, and is notable for being adjacent and bright. When Chen was fixed 12 hours of observations with Webb, she wanted to spell backmost and look astatine the aforesaid prima system, Beta Pictoris, that had intrigued her for each those years. This time, however, the prima strategy didn’t look each that familiar. “I was like, ‘oh my gosh, the features are gone,’” Chen told Gizmodo. “Is this real? And if it is, past what happened?” Through the Webb observations, Chen, who pb the caller study, and her squad focused connected vigor emitted by crystalline silicates—minerals commonly recovered astir young stars—and recovered nary traces of the particles antecedently seen successful 2004 and 2005. “Whenever astronomers look astatine the entity and they spot something, we ever presume that everything is successful dependable state, that it’s not changing,” Chen said. “The crushed wherefore we deliberation that is due to the fact that if you deliberation astir the peculiar instant that you’re looking at, that’s precise abbrevi...

Study Confirms Einstein Prediction: Black Holes Have a 'Plunging Region': "Albert Einstein was right," reports CNN. "There is an area at the edge of black holes where matter can no longer stay in orbit and instead falls in, as predicted by his theory of gravity." The proof came by combining NASA's earth-orbiting NuSTAR telescope with the NICER telescope on the International Space Station to detect X-rays: A team of astronomers has for the first time observed this area — called the "plunging region" — in a black hole about 10,000 light-years from Earth. "We've been ignoring this region, because we didn't have the data," said research scientist Andrew Mummery, lead author of the study published Thursday in the journal Monthly Notices of the Royal Astronomical Society. "But now that we do, we couldn't explain it any other way." Mummery — also a Fellow in Oxford's physics department — told CNN, "We went out searching for this one specifically — that was always the plan. We've argued about whether we'd ever be able to find it for a really long time. People said it would be impossible, so confirming it's there is really exciting." Mummery described the plunging region as "like the edge of a waterfall." Unlike the event horizon, which is closer to the center of the black hole and doesn't let anything escape, including light and radiation, in the "plunging region" light can still escape, but matter is doomed by the powerful gravitational pull, Mummery explained. The study's findings could help astronomers better understand the formation and evolution of black holes. "We can really learn about them by studying this region, because it's right at the edge, so it gives us the most information," Mummery said... According to Christopher Reynolds, a professor of astronomy at the University of Maryland, College Park, finding actual evidence for the "plunging region" is an important step that will let scientists significantly refine models for how matter behaves around a black hole. "For example, it can be used to measure the rotation rate of the black hole," said Reynolds, who was not involved in the study. Read more of this story at Slashdot.

Do you know what would happen when a planet as giant as Jupiter passes in front of its parent star? If you have been measuring the amount of light coming from this star, also known as its luminosity, you will notice a drop of about 1% in its brightness. This method, called Transit Photometry, is one of the most common techniques scientists use to find new planets. The Kepler Space Telescope scanned the sky for such planets using the transit photometry method. The space telescope monitored the light curves of 100,000 stars in a patch of sky in the Cygnus and Lyra constellations. Based on the data collected by the Kepler mission, scientists associated with the Planet Hunters Project found a star that was dimming by 22%. I know what you’re thinking: if a planet as big as Jupiter could cause a dip in the brightness of a star by only 1%, then what could justify a whopping 22% dip? This would mean that whatever is causing the dip is 1000 times bigger than Earth. Even more interesting is that the individuals associated with the Planet Hunters Project who made this discovery were not your typical professional astronomers, but citizen scientists. Tabetha Boyajian, a professional astronomer heading the Planet Hunters Project, proclaimed the fluctuations in a research paper published in 2015. The paper had one of the most interesting, or rather juicy, titles in the world. It was aptly called the WTF: Where’s the Flux? paper, referring to the missing flux of the star. The announcement of a star as bizarre as this one took the astronomy world by storm and catalyzed a series of investigations globally. Astronomers, across the world, rolled up their sleeves and got their telescopes ready to investigate the weirdest star they had ever known. Everybody saw this as an opportunity to feel the awe of discovery and a chance to solve one of the greatest mysteries in astronomy and astrophysics. Based on the Kepler Input Catalog data, they named the star KIC 8462852. KIC 8462852, also known as Tabby’s Star, is a binary star located in the Cygnus constellation. As per the Astronomers Tabby’s star is a F-type main-sequence star with a red dwarf companion. The star is located some 1470 light years away and was first observed in 1890. What makes this star the weirdest ever is not only its sharp dip in luminosity but also the aperiodic fluctuations that keep happening from time to time. After the first dimming reported in 2009, the star went on a luminosity vacation, behaving normally for two years. And then comes March 2011 when the luminosity dropped by 15%. Read the entire article here on medium: https://shorturl.at/9SHaV

#astronomy An article published in the journal "Nature Astronomy" reports the identification of the #exoplanet WASP-193 b, a gas giant whose diameter is approximately 1.5 times Jupiter's but with a mass that is only one-seventh of Jupiter's. A team of researchers led by Khalid Barkaoui of the University of Liège, Belgium, used the WASP-South telescope of the Wide Angle Search for Planets (WASP) collaboration to locate WASP-193 b and then study its characteristics with other instruments. The combination of this exoplanet's mass and density is really difficult to explain since no theory of planetary formation leads to a planet like this. https://lnkd.in/dJKnhvJp

Study Confirms Einstein Prediction: Black Holes Have a 'Plunging Region': "Albert Einstein was right," reports CNN. "There is an area at the edge of black holes where matter can no longer stay in orbit and instead falls in, as predicted by his theory of gravity." The proof came by combining NASA's earth-orbiting NuSTAR telescope with the NICER telescope on the International Space Station to detect X-rays: A team of astronomers has for the first time observed this area — called the "plunging region" — in a black hole about 10,000 light-years from Earth. "We've been ignoring this region, because we didn't have the data," said research scientist Andrew Mummery, lead author of the study published Thursday in the journal Monthly Notices of the Royal Astronomical Society. "But now that we do, we couldn't explain it any other way." Mummery — also a Fellow in Oxford's physics department — told CNN, "We went out searching for this one specifically — that was always the plan. We've argued about whether we'd ever be able to find it for a really long time. People said it would be impossible, so confirming it's there is really exciting." Mummery described the plunging region as "like the edge of a waterfall." Unlike the event horizon, which is closer to the center of the black hole and doesn't let anything escape, including light and radiation, in the "plunging region" light can still escape, but matter is doomed by the powerful gravitational pull, Mummery explained. The study's findings could help astronomers better understand the formation and evolution of black holes. "We can really learn about them by studying this region, because it's right at the edge, so it gives us the most information," Mummery said... According to Christopher Reynolds, a professor of astronomy at the University of Maryland, College Park, finding actual evidence for the "plunging region" is an important step that will let scientists significantly refine models for how matter behaves around a black hole. "For example, it can be used to measure the rotation rate of the black hole," said Reynolds, who was not involved in the study. Read more of this story at Slashdot.

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