Universe Today

June 21, 2023June 21, 2023 by Andy Tomaswick

A New Mission Will Grab Dead Satellites and Push Them Into the Atmosphere to Burn Up

Plenty of news stories have focused on the danger posed by Kessler syndrome. In this condition, space is made inaccessible by a cloud of debris surrounding our planet that would destroy any further attempts to get into orbit. Therefore, plenty of companies have sprung up that problem to take care of the problem, from blasting derelict satellites with lasers to helping to refuel them; lots of business models have been created to capture this opportunity. One of the farthest along is Astroscale. This British start-up is tackling the problem with one of the more conventional techniques – linking up with an existing satellite to deorbit it. And recently, they released a promotional video for their new project – the ELSA-M.

June 20, 2023June 20, 2023 by Carolyn Collins Petersen

Astronomers Find a White Dwarf Pulsar

An artist's conception of a white dwarf pulsar pair. Two are now known. Credit: University of Warwick.

When astronomers talk about the “end states” of stellar evolution, several categories come to mind: black holes, neutron stars/pulsars, and white dwarfs. What happens if one star ends up in two of these states? That’s the case with a genre-breaking white dwarf pulsar called J191213.72-441045.1 (J1912-4410 for short). It’s part of a binary pair that includes a red dwarf star.

June 20, 2023June 20, 2023 by Matt Williams

JWST Glimpses the Cosmic Dawn of the Universe

This still image shows the timeline running from the Big Bang on the right, towards the present on the left. In the middle is the Reionization Period where the initial bubbles caused the cosmic dawn. Credit: NASA SVS

The James Webb Space Telescope (JWST) continues to push the boundaries of astronomy and cosmology, the very job it was created for. First conceived during the 1990s, and with development commencing about a decade later, the purpose of this next-generation telescope is to pick up where Spitzer and the venerable Hubble Space Telescope (HST) left off – examining the infrared Universe and looking farther back in time than ever before. One of the chief objectives of Webb is to observe high-redshift (high-Z) galaxies that formed during Cosmic Dawn.

This period refers to the Epoch of Reionization, where the first galaxies emitted large amounts of ultraviolet (UV) photons that ionized the neutral hydrogen that made up the intergalactic medium (IGM), causing the Universe to become transparent. The best way to measure the level of star formation is the H-alpha emission line, which is visible in the mid-infrared spectrum for galaxies with high redshifts. Using data from the Mid-Infrared Instrument (MIRI), an international team of researchers was able to resolve the H-alpha line and observe galaxies with redshift values higher than seven (z>7) for the first time.

June 20, 2023June 20, 2023 by Nancy Atkinson

The Suspense is Killing Us. The Next Planet in the TRAPPIST System Gets the JWST Treatment

This artist' concept shows what the hot rocky exoplanet TRAPPIST-1 c could look like based on observations by the James Webb Space Telescope. TRAPPIST-1 c, the second of seven known planets in the TRAPPIST-1 system, orbits its star at a distance of 0.016 AU (about 1.5 million miles), completing one circuit in just 2.42 Earth-days. Credits: NASA, ESA, CSA, Joseph Olmsted (STScI)

The TRAPPIST-1 system is easily the most exciting collection of exoplanets ever discovered by astronomers. The system contains seven rocky planets orbiting an ultracool red dwarf star 40 light-years from Earth. Several of the planets are in the star’s habitable zone.

With the James Webb Space Telescope’s ability to detect and study the atmospheres of distant planets orbiting other stars, data on the TRAPPIST planets have been highly anticipated. Astronomers have now released detailed information about the second planet, TRAPPIST-1 c, theorized to be a Venus-like world. Unlike Venus, however, JWST failed to detect any trace of a thick carbon dioxide atmosphere.

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.