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Astronomers Discover Planets Building Each Other in Space By Frederic Eger - Illustration: Radio astronomy has revealed that early-formed planets within a protoplanetary disk can influence the creation of additional planets, acting like a cascade where each planet aids in forming the next - Credit: SciTechDaily.com - Astronomers have published a paper in National Institutes of Natural Sciences as they have discovered that early-formed planets within a protoplanetary disk can influence the creation of additional planets, acting like a cascade where each planet aids in forming the next. This finding, based on high-resolution images from the Atacama Large Millimeter/submillimeter Array (ALMA), supports the domino effect in the sequential formation of planetary systems. So far, astronomers have identified over 5,500 planetary systems, with more than 1,000 confirmed to have multiple planets. Planets form in protoplanetary disks, massive clouds of gas and dust surrounding young stars. The exact process of how multi-planet systems like our Solar System develop remains unclear. A key system for studying planet formation is PDS 70, a young star located 367 light-years away in the constellation Centaurus. Earlier radio wave observations from the Atacama Large Millimeter/submillimeter Array (ALMA) detected a ring of dust grains beyond the orbits of PDS 70’s two known planets. However, these initial observations lacked the resolution needed to explore the ring’s detailed structure. In this research, an international team led by Kiyoaki Doi performed high-resolution observations of the protoplanetary disk around PDS 70 using ALMA at a longer wavelength of radio waves. The new ALMA observations clearly show a concentration of dust grains to the northwest (upper right) in the ring outside the orbits of the two existing planets. The location of this dust clump suggests that the already-formed planets interact with the surrounding disk, concentrating dust grains into a narrow region at the outer edge of their orbits. These clumped dust grains are thought to grow into a new planet. This work observationally shows that the formation of planetary systems, like the Solar System, can be explained by the sequential formation of the planets from inside to outside by the repetition of this process; like a line of falling dominos, each one triggering the next.

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)

#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.

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

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.

[Hubble Telescope Peeks At Star With Planet-Forming Disk That Gets 3 Times Hotter Than The Sun] A star about 1,360 light-years away from Earth, named FU Orionis, is twice as hot as astronomers previously suspected, according to recent data from the Hubble Space Telescope. Caltech astronomer Adolfo Carvalho and his colleagues suggest the area around the star is so surprisingly hot because a rapidly-spinning disk of material falling into the star is actually scraping against its surface, creating a shockwave that glows a hundred times brighter than the star itself. And that could create a rough environment for Earth-like planets; the star's interaction with the disk of material around it is just too explosive for a planet like Earth or Mars, for that matter to form. A bright, but strange, young star The bright variable star FU Orionis is one of a bizarre class of newly-formed stars. Like most young stars, it's surrounded by a glowing disk of gas and dust, which will eventually coalesce into planets. But FU Orionis is still feeding on its disk, growing larger by consuming material that would otherwise be the building blocks of a system of planets. As the gas and dust in FU Orionis's accretion disk spirals toward the star, it speeds up, causing the disk to glow the hallmark of what astronomers call a "T Tauri star." However, FU Orionis is weird even for a T Tauri star, because its disk is unstable. That may be because there's so much material in the disk that it becomes unbalanced; it may also be because FU Orionis is part of a binary system, influenced by the gravitational pull of a second star. Either way, the speeding inner edge of the accretion disk sometimes scrapes against the much slower-moving surface of the star, releasing a burst of heat and light. These outbursts, as they're called, can last for decades; FU Orionis has been having one since 1936, when the star first flared to a hundred times its original brightness over just a few months. Typically, astronomers only see a star change so quickly when it dies in a supernova however, unlike a supernova, FU Orionis has dimmed only slightly over the last 88 years. Astronomers then realized the bright glow they saw wasn't starlight, but rather the glow of the disk of material swirling faster and faster around the star, pouring electrically charged gas called plasma onto the surface of the star and outshining FU Orionis itself. Since then, astronomers have wondered exactly what happened at the place where the inner edge of the disk scrapes against the surface of the star. They've built computer simulations of the physics involved, hoping to predict how the whole system works in detail. Source: https://lnkd.in/ekksTt-v #galaxyaerosgh #space #spaceexploration #SpaceNews

The cotton candy-like planet. Researchers led by Khalid Barkaoui from the EXOTIC Laboratory of the University of Liège, in collaboration with MIT and the Astrophysics Institute in Andalusia, have discovered an exoplanet with the density of cotton candy. WASP-193b, located orbiting a Sub-like star 1200 light-years away, was discovered by the Wide Angle Search for Planets (WASP) collaboration. Follow up observations from the TRAPPIST-South and SPECULOOS-South observatories, as well as the HARPS and CORALIE spectrographs of the European Southern Observatory (ESO), permitted to determine that it was 50% larger than Jupiter, but seven times less massive. The resulting density is about 0.06 grams per cubic centimeter, less than Jupiter (1.33), and much less than Earth (5.51). In fact, no current model can satisfactorily explain how such a planet could be formed, but the researchers suspect it's made mostly of hydrogen and helium. The findings have been published in Nature Astronomy (14 May, 2024). https://lnkd.in/dQTj7EMf #physics #physicsnews #astronomy #astrophysics #exoplanets #wasp193b

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