Vera Rubin Will Find Many More Interstellar Objects

By Brian Koberlein - August 13, 2023 04:05 PM UTC | Missions
Astronomers have discovered two interstellar objects, Oumuamua and 2I/Borisov. When the Vera C Rubin Observatory comes online next year, it'll scan the entire southern sky every few nights, revealing thousands of comets and asteroids. Some fraction of these will be interstellar objects, passing briefly through the Solar System. It's estimated that Vera Rubin will discover dozens of interstellar objects, some of which might make the perfect targets for an interceptor mission.
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Giant Tidal Waves are Crashing Onto the Surface of an Enormous Star

By Brian Koberlein - August 12, 2023 01:39 PM UTC | Stars
Although the surface of a star seems quite different from the ocean, the underlying effect of gravity can create similar conditions. One type of star is known as a "heartbeat star," where a binary system interacts with one another, generating enormous stellar tides from their mutual gravity. In one extreme system, the gravitational effect is 200 times larger than any heartbeat star seen before. An enormous wave is generated across the star as its binary companion approaches. Like ocean waves, these waves break, crashing down onto the star's surface.
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Evidence for Modified Gravity Found in the Motions of Binary Stars

By Brian Koberlein - August 11, 2023 02:09 PM UTC | Physics
There are two leading explanations for dark matter, massive particles that don't interact with regular matter apart from gravity and a subtle difference in how gravity behaves at large distances. Astronomers have studied the interactions of over 20,000 binary stars with wide orbits cataloged in Gaia data. They found that orbital accelerations of the stars match the predictions made by modified Newtonian gravity and provide compelling evidence for the MOND hypothesis over the dark matter being a particle.
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Astronomers Search for Dark Matter Annihilation at the Center of the Earth

By Brian Koberlein - August 10, 2023 12:52 PM UTC | Physics
If dark matter is made of heavy particles, they could become captured by the gravitational field of massive objects like stars or planets. Constrained in a small area, these particles could crash into one another and annihilate with radiation. Astronomers have searched through 10 years of data captured by the IceCube Neutrino Observatory at the South Pole for any evidence of this dark matter annihilation. Although they didn't detect any evidence, the next generation IceCube Update will significantly improve the search.
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Could This Supermassive Black Hole Only Have Formed by Direct Collapse?

By Brian Koberlein - August 09, 2023 01:15 PM UTC | Black Holes
One of the outstanding mysteries in astronomy is how supermassive black holes gained so much mass so early in the Universe. The traditional theory is that stellar mass black holes merge, building up to supermassive levels. Another theory suggests that supermassive black holes might have collapsed directly out of enormous clouds of gas and dust. Astronomers using JWST and Chandra think they've discovered a black hole that's too massive, too early, and could only have formed from direct collapse.
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Some Metal Meteorites Have a Tiny Magnetic Field. But How?

By Brian Koberlein - August 06, 2023 01:00 PM UTC | Planetary Science
A portion of the metallic meteorites found on Earth have traces of magnetism. This is surprising since you need a larger world with an internal dynamo like the Earth. New research suggests that iron-heavy asteroids can collect into piles of rubble, with other space rocks forming a cold inner pile surrounded by a warmer liquid outer layer. As the core draws heat from the outer layer, it initiates convection and a small magnetic field that is detectable in the iron meteorites billions of years later.
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Do Technological Civilizations Depend on Atmospheric Oxygen?

By Brian Koberlein - August 05, 2023 12:54 PM UTC | Astrobiology
Our modern technological civilization wouldn't have been possible without open-air combustion, which can only happen when atmospheric oxygen levels reach at least 18%. A new study asks if this could be a bottleneck for developing other advanced civilizations. Without at least 18% oxygen, fires won't easily burn, so technologies like steam power and combustion engines wouldn't be possible. Earth has only reached that level of atmospheric composition in the last 500 million years.
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JWST is the Perfect Machine to Resolve the Hubble Tension

By Brian Koberlein - August 04, 2023 12:31 PM UTC | Cosmology
Over the last decade, various measurements have disagreed over the rate that the Universe is expanding. Astronomers use Cepheid variables as standard candles to measure relatively nearby galaxies and then use them to calibrate more distant candles like Type 1a supernovae. The most accurate measurements have been done with the Hubble Space Telescope, but a new survey of 330 Cepheid variables has been done with JWST, narrowing down the error bars even more and building a perfect distance ladder to Type 1a supernovae.
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Does the Milky Way's Supermassive Black Hole Have a Companion?

By Brian Koberlein - August 03, 2023 07:56 AM UTC | Milky Way
Astronomers have found stellar mass and supermassive black holes, but they're still on the hunt for an intermediate size; black holes with thousands of times the mass of the Sun. One natural place to look is at the heart of the Milky Way, near our galaxy's supermassive black hole. Researchers have examined the region around the galactic core and the movement of stars whipping around the central black hole. Although they didn't find evidence for a companion black hole, they've set size constraints on what could be there.
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Euclid Reaches L2, Shares its First Test Image

By Brian Koberlein - August 02, 2023 10:08 AM UTC | Missions
ESA's Euclid mission has made the journey through space to reach the Earth-Sun L2 Lagrange Point. The two instruments on board have come online and taken their first images of the cosmos. The left side of the image was taken by the VISible instrument (VIS), which will help astronomers study the shapes of billions of galaxies. The right side of the image was taken with the Near-Infrared Spectrometer and Photometer, which allows astronomers to measure the brightness and color of galaxies. Astronomers will use these instruments to make the most comprehensive 3D map of the Universe, hunting for dark matter and energy.
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What Does 60 Years of Silence Tell Us About the Search for Extraterrestrials?

By Brian Koberlein - August 01, 2023 10:41 AM UTC | Astrobiology
Astronomers have only been scanning the skies for a signal from extraterrestrial civilizations for about 60 years. Although no signal has been found, a new study suggests that this lack of detection can help us predict what the future holds for SETI. According to their analysis, this means there's a 50% probability that Earth won't detect signals for the next 60 to 1800 years.
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