The Best Way to Find Planet Nine Might Be Hundreds of Tiny Telescopes

By Brian Koberlein - November 15, 2024 03:46 PM UTC | Planetary Science
Although the outer Solar System is mostly empty, there are icy objects drifting within the very limits of detection by our largest telescopes. But maybe small telescopes can be more successful. A new paper suggests that an array of 200 automated 40-cm telescopes spread across 1,000 km could be the best way to find them. They would watch for changes in brightness as objects pass in front of stars and could even find the hypothetical Planet Nine.
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A New Look a the Most Ancient Light in the Universe

By Brian Koberlein - November 15, 2024 01:54 PM UTC | Cosmology
About 370,000 years after the Big Bang, the Universe had cooled down so light could escape, traveling for billions of years to reach our telescopes. This is the Cosmic Microwave Background Radiation, and the very last light released is known as "last scattering," when reflected, polarized light was released. New observations from the South Pole Telescope have completed a comprehensive survey of this polarized light, revealing more about the Universe's earliest history.
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Two Supermassive Black Holes on the Verge of a Merger

By Brian Koberlein - November 14, 2024 01:43 PM UTC | Black Holes
Researchers have been keeping an eye on the center of a galaxy located about a billion light-years away. Every few months, the galaxy center releases a flash of X-rays, which appears to be coming from a pair of supermassive black holes orbiting one another. They're only about a light-day apart and contain a combined 40 million solar masses. They take 130 days to orbit and are expected to collide in about 70,000 years.
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Astronomers Map the Shape of a Black Hole's Corona for the First Time

By Brian Koberlein - November 14, 2024 11:24 AM UTC | Black Holes
The Sun is surrounded by the corona, a region of superheated gas above the surface that can be millions of degrees. Black holes have them too, but they can be billions of degrees. Astronomers have used NASA's IPXE mission to map the shape of a black hole corona for the first time. They found the corona matches the shape of the accretion disk feeding material into the black hole, and not a giant sphere that surrounds the region.
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Astronomers Defy the Zone of Avoidance to Find Hundreds of New Galaxies

By Brian Koberlein - November 13, 2024 10:23 AM UTC | Extragalactic
The Zone of Avoidance is a region of the sky that's obscured by the disk of the Milky Way. The gas and dust block our view in visible telescopes, but other wavelengths like radio and infrared can pierce it to see what's on the other side. Astronomers used the MeerKAT radio telescope to survey beyond the Zone, observing hundreds of galaxies, of which only 29% were already known. This is helping to map the Great Attractor galaxy cluster on the far side of the Milky Way.
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How Webb Stays in Focus

By Brian Koberlein - November 10, 2024 11:32 AM UTC | Telescopes
JWST's primary mirror consists of 18 individual segments, each of which can be moved on 6 different axes of freedom. This allows the telescope to maintain perfect focus, despite changing temperatures and micrometeorite strikes on its optics. The objective was 150 nanometers of wavefront error, but the current error is down to just 65 nanometers. In early October, engineers measured the telescope's jitter and refocused it again, bringing it to its perfect alignment
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Using Light Echoes to Find Black Holes

By Brian Koberlein - November 09, 2024 12:39 PM UTC | Black Holes
The speed of light gives astronomers a special trick when examining the tangled-up gravitational well around a black hole. Researchers have proposed that they can measure the spin of a black hole because of the bizarre path that photons take in their vicinity, released by accreting matter. Some photons blast straight out, while others are lensed indirectly, and some travel around the black hole twice before escaping, hinting at the black hole's rotation rate.
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An Explanation for Rogue Planets. They Were Eroded Down by Hot Stars

By Brian Koberlein - November 08, 2024 11:06 AM UTC | Exoplanets
WST recently turned up hundreds of free-floating rogue planets in the Orion Nebula, 42 in binary configurations. How two Jupiter-mass objects could end up orbiting one another has puzzled astronomers, but now a team of researchers thinks they know it happens. Large, hot stars in the Orion Nebula blasted the outer layers of smaller stars, eroding them away and preventing them from gaining enough mass to ignite fusion in their cores - even binary stars.
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How Many Additional Exoplanets are in Known Systems?

By Brian Koberlein - November 05, 2024 10:05 AM UTC | Exoplanets
NASA's TESS mission has turned up thousands of exoplanet candidates in almost as many different star systems. But if one or two planets show up in a system, that means it's aligned with Earth, and that means we should be able to see even more in the same system. In a new paper, astronomers calculate which planetary systems have room for more exoplanets, creating a list of priority targets for further study.
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