Universe Today

June 20, 2023June 20, 2023 by Brian Koberlein

An Unfortunate Planet is Undergoing “Extreme Evaporation,” Melting Under the Extreme Heat From its Star

Illustration of a bursting planet about to flare. Credit: Sergei Nayakshin/Vardan Elbakyan, University of Leicester

FU Orionis is an unusual variable star. It was first seen as a magnitude 16 star in the early 1900s, but in the mid-1930s it rapidly brightened to a magnitude 9 star. The rapid brightening of a star was not unheard of, but in this case, FU Orionis did not fade to its original brightness. Since 1937 it has remained around magnitude 9, varying only slightly over time. For decades the mysterious star was thought to be unique, but in the 1970s similar stars were observed, and are now known as FU Orionis objects. Astronomers still had no real idea what could cause such a dramatic change, but a new study argues that it could be caused by a dying young planet.

June 19, 2023June 19, 2023 by Andy Tomaswick

Can We Predict if a System Will Have Giant Planets?

Prediction is one of the hallmarks of scientific endeavors. Scientists pride themselves on being able to predict physical realities based on inputs. So it should come as no surprise that a team of scientists at Notre Dame has developed a theory that can be used to predict the existence of giant planets on the fringes of an exoplanetary system.

June 19, 2023June 19, 2023 by Carolyn Collins Petersen

The Evidence is Building that Dark Matter is Made of Axions

In shaping the Universe, gravity builds a vast cobweb-like structure of filaments tying galaxies and clusters of galaxies together along invisible bridges hundreds of millions of light-years long. A galaxy can move into and out of the densest parts of this web throughout its lifetime. Credit: Volker Springel (Max Planck Institute for Astrophysics) et al.

There’s some potentially big news on the hunt for dark matter. Astronomers may have a handle on what makes this mysterious cosmic stuff: strange particles called “axions.”

June 19, 2023June 19, 2023 by Brian Koberlein

Astronomers Have Never Detected Merging Supermassive Black Holes. That Might Be About to Change

Simulation of merging supermassive black holes. Credit: NASA's Goddard Space Flight Center/Scott Noble — Simulation of merging supermassive black holes. New research shows how dark matter overcomes the Final Parsec Problem. Credit: NASA's Goddard Space Flight Center/Scott Noble

Gravitational wave astronomy currently can only detect powerful rapid events, such as the mergers of neutron stars or stellar mass black holes. We’ve been very successful in detecting the mergers of stellar mass black holes, but a long-term goal is to detect the mergers of supermassive black holes.

June 19, 2023June 19, 2023 by Andy Tomaswick

Even Though They’re Bigger, Generation 2 Starlinks are Fainter than Gen 1

We’ve filed plenty of reports here at UT warning about the potential impact of Starlink and similar satellites on the field of astronomy. We’ve gone so far as to point out that the granddaddy of space-based telescopes – Hubble – has already had some of its images tarnished by passing Starlink satellites. However, SpaceX has been aware of the problem and is working to limit their product’s brightness. The recently launched Gen2 satellites seem to have made a significant step forward – research from a team of amateur astronomers finds that the new Gen2 Starlinks are more than 10x fainter than previous Gen1 iterations.

June 18, 2023June 18, 2023 by Matt Williams

Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens

A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI

Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.

In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.

June 17, 2023June 11, 2023 by Paul M. Sutter

The Best Particle Collider in the World? The Sun

A look inside ALICE at the Large Hadron Collider. ALICE is one of the LHC's four particle detectors. Image: CERN/LHC

Recently astronomers caught a strange mystery: extremely high-energy particles spitting out of the surface of the Sun when it was relatively calm. Now a team of theorists have proposed a simple solution to the mystery. We just have to look a little bit under the surface.

June 17, 2023June 17, 2023 by Scott Alan Johnston

We Could See the Glint off Giant Cities on Alien Worlds

How large would an extraterrestrial city have to be for current telescopes to see it? Would it need to be a planet-sized metropolis like Star Wars’ Coruscant? Or could we see an alien equivalent of Earth’s own largest urban areas, like New York City or Tokyo?

A recent preprint by Bhavesh Jaiswal of the Indian Institute of Science suggests that, in fact, we could see cities a mere fraction of that size, using a feature of light known as specular reflection.

June 17, 2023June 17, 2023 by Brian Koberlein

JWST is Powerful Enough to See a Variety of Biosignatures in Exoplanets

Spectra of an exoplanet atmosphere. Credit: NASA, ESA, CSA, STScI

The best hope for finding life on another world isn’t listening for coded messages or traveling to distant stars, it’s detecting the chemical signs of life in exoplanet atmospheres. This long hoped-for achievement is often thought to be beyond our current observatories, but a new study argues that the James Webb Space Telescope (JWST) could pull it off.

June 16, 2023June 11, 2023 by Paul M. Sutter

The Hidden Benefits of Large Science Projects

Ten areas in the sky were selected as “deep fields” that the Dark Energy Camera imaged several times during the survey, providing a glimpse of distant galaxies and helping determine their 3D distribution in the cosmos. Credit: NSF/DES/NOIRLab/DOE/FNAL/AURA/University of Alaska Anchorage/

Large astronomical projects like the Dark Energy Survey and the James Webb Space Telescope provide innumerable benefits to society, like technological spin-offs, national prestige, and a way to satisfy our common human curiosity.