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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New Simulation Reveals the Churning Interiors of Giant Stars

By Brian Koberlein - July 30, 2023 12:12 PM UTC | Stars
Stellar fusion happens at a star's core, where the enormous temperatures and pressures fuse hydrogen atoms into helium, releasing radiation. Waves of turbulent convection generated in the core can take hundreds of thousands of years to ripple outward through the stars' layers, finally reaching the surface. A new simulation shows waves generated deep inside stars, more massive than the Sun, make their way to the surface and affect the star's brightness.
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Chinese Scientists Complete a Concept Study for a 6-Meter Space Telescope to Find Habitable Exoplanets

By Brian Koberlein - July 29, 2023 02:25 PM UTC | Exoplanets
With JWST safely in space, researchers are designing the next generation of space telescope that could Earth-sized worlds orbiting sunlike stars. Chinese scientists released a concept paper this week for the Tianlin mission, a 6-meter UV/Optical/IR space telescope, which could begin operations in 2045. This telescope would search for rocky planets in the habitable zones around nearby stars and search for biosignatures using direct imaging. The team estimates they could obtain the spectrum of 20 candidate exoplanets in the first five years of operation.
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Clumps Around a Young Star Could Eventually Turn Into Planets Like Jupiter

By Brian Koberlein - July 28, 2023 12:29 PM UTC | Exoplanets
New images from the European Southern Observatory show a young star surrounded by dusty clumps that could collapse and create giant planets like Jupiter. The star is V960 Mon, located about 5,000 light-years away in the constellation Monoceros. The star brightened suddenly in 2014, leading astronomers to conclude it's assembling spiral arms in its protoplanetary disk. The new observations show that these arms are fragmenting into clumps, with masses similar to giant planets.
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A Gamma Ray Burst Lasted So Long it Triggered a Satellite Twice

By Brian Koberlein - July 26, 2023 04:39 PM UTC | Extragalactic
amma-ray bursts are the most powerful explosions in the Universe, briefly outshining all the stars in their galaxy combined. They typically last for just seconds or a few minutes at the most. In 2022, an ultra-long gamma-ray burst exploded in the sky, lasting so long, with two separate blasts of radiation that it triggered the Fermi Gamma-Ray Burst Monitor twice. The blast was clocked at almost 1000 seconds, with a double blast that made some astronomers wonder if it was due to a gravitational lens.
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Astronomers Have a New Trick to Work out the Age of Stars

By Brian Koberlein - July 25, 2023 12:11 PM UTC | Stars
Determining the age of a star is surprisingly tricky and has wide error bars. It's only inside star clusters that you get a chance to accurately measure a star's age since they all had the exact origin and age. But a new technique hopes to discover the age of stars by measuring their rotation. As stars get older, their rotation rate slows down. By plotting the rotation rates of stars in clusters against their known ages, they can apply it to individual stars which aren't in clusters.
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Venus Needed Asteroid Impacts to Get its Volcanoes Going

By Brian Koberlein - July 24, 2023 01:11 PM UTC | Planetary Science
Unlike Earth, Venus lacks the plate tectonics that give rise to volcanoes. But the surface of Venus looks far younger than other worlds, like Mars or the Moon, which means it does have volcanic activity that regularly resurfaces the planet. Because Venus is closer to the Sun, it came farther out in the Solar System and hit the planet at higher velocities. A new study suggests that early catastrophic asteroid impacts melted its mantle, leading to its flavor of volcanism.
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One Side of This White Dwarf is Covered in Hydrogen While the Other Side is Helium.

By Brian Koberlein - July 21, 2023 01:15 PM UTC | Stars
Here's a new one. Astronomers have found a white dwarf star - the dead remnant from a main sequence star like the Sun - with one hemisphere composed of hydrogen while the other is covered in helium. The star was discovered with the Zwicky Transient Facility, revealing that it rotates every 15 minutes. Spectroscopic data unveiled its two-sided nature. What?! Also. How?! Some white dwarfs transition from hydrogen- to helium-dominated surfaces, and astronomers might have caught it in the act.
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