Astronomy Archives

November 11, 2022November 11, 2022 by Matt Williams

This Nearby Dwarf Galaxy has Been a Loner for Almost the Entire age of the Universe

Wolf-Lundmark-Melotte as seen by the VLT Survey Telescope. Ctedit: ESO

The James Webb Space Telescope Early Release Science (ERS) program – first released on July 12th, 2022 – has proven to be a treasure trove of scientific finds and breakthroughs. Among the many areas of research it is enabling, there’s the study of Resolved Stellar Populations (RSTs), which was the subject of ERS 1334. This refers to large groups of stars close enough that individual stars can be discerned but far enough apart that telescopes can capture many of them at once. A good example is the Wolf-Lundmark-Melotte (WLM) dwarf galaxy that neighbors the Milky Way.

Kristen McQuinn, an assistant professor of astrophysics at Rutgers University, is one of the lead scientists of the Webb ERS program whose work is focused on RSTs. Recently, she spoke to Natasha Piro, a NASA senior communications specialist, about how the JWST has enabled new studies of the WLM. Webb‘s improved observations have revealed that this galaxy hasn’t interacted with other galaxies in the past. According to McQuinn, this makes it a great candidate for astronomers to test theories of galaxy formation and evolution. Here are the highlights of that interview:

November 10, 2022November 10, 2022 by Scott Alan Johnston

Keck's new Planet Hunter Instrument Comes Online, Searching for Smaller, More Earth-Sized Exoplanets

There’s a new planet hunter in town, and it’s got its sights set on nearby Earth-sized planets in the galactic neighborhood.

November 9, 2022November 9, 2022 by Matt Williams

The Case of the “Missing Exoplanets”

An illustration of the variations among the more than 5,000 known exoplanets discovered since the 1990s. Could their stars' metallicity play a role in making them habitable to life? Credit: NASA/JPL-Caltech

Today, the number of confirmed exoplanets stands at 5,197 in 3,888 planetary systems, with another 8,992 candidates awaiting confirmation. The majority have been particularly massive planets, ranging from Jupiter and Neptune-sized gas giants, which have radii about 2.5 times that of Earth. Another statistically significant population has been rocky planets that measure about 1.4 Earth radii (aka. “Super-Earths”). This presents a mystery to astronomers, especially where the exoplanets discovered by the venerable Kepler Space Telescope are concerned.

Of the more than 2,600 planets Kepler discovered, there’s an apparent rarity of exoplanets with a radius of about 1.8 times that of Earth – which they refer to as the “radius valley.” A second mystery, known as “peas in a pod,” refers to neighboring planets of similar size found in hundreds of planetary systems with harmonious orbits. In a study led by the Cycles of Life-Essential Volatile Elements in Rocky Planets (CLEVER) project at Rice University, an international team of astrophysicists provide a new model that accounts for the interplay of forces acting on newborn planets that could explain these two mysteries.

November 9, 2022November 2, 2022 by Paul M. Sutter

Chipping Away at the Great Attractor Mystery. Another Galaxy Cluster Found Behind the Milky Way’s Disk

At the very centre of the simulation (and our own Universe) is the Milky Way galaxy, and our nearest massive neighbour, the Andromeda galaxy (known as M31). Credit Dr Stuart McAlpine

Something huge lurks in the shadows of the Universe. Known as the Great Attractor, it is causing the Milky Way and all the surrounding galaxies to rush towards it. We would normally have a better understanding of this situation, except for the fact that the Great Attractor happens to lie in the direction behind the galactic bulge, which makes it difficult for us to observe. A team of astronomers have performed a new infrared survey of the region behind the bulge, and they have found yet another large galaxy cluster. Their work is helping to paint a more complete portrait of the environment of the Great Attractor.

November 8, 2022November 2, 2022 by Paul M. Sutter

Check Out the Journey From Raw Data to Beautiful Image

Every step in the pipeline from raw data to an image of the Vela supernova remnant taken with the VST Survey Telescope (Image credit: ESA)

Creating astronomical images is no easy task, and astronomers with the European Southern Observatory have provided a handy guide to show you how astronomy goes from raw data to an image that you can splash on your desktop.

November 8, 2022November 8, 2022 by Brian Koberlein

Astronomers Spot the Debris From Planets That Formed 10 Billion Years ago

Artist's view of old white dwarfs surrounded by planetary debris. Credit: University of Warwick/Dr Mark Garlick

The fate of the Sun is sealed. It was sealed by gravity in the earliest days of its formation. In several billion years the Sun will swell to a red giant, cast off much of its thin outer layers, then collapse to become a white dwarf. The white dwarfs we see in the nearby galaxy tell us of our Sun’s future. Its core will collapse to about the size of Earth, and then it will gradually cool as it fades into the dark. It’s a tale we’ve long known, but astronomers continue to learn learning interesting details, particularly regarding what might be the fate of the Sun’s planets.

November 8, 2022November 6, 2022 by Scott Alan Johnston

The Smallest Radar Ever Sent to Space Will Probe the Interior of Dimorphos After its Impact From DART

Are miniature probes the future of deep space exploration?

November 7, 2022November 11, 2022 by Paul M. Sutter

Meet The Solar Ring: A Proposed Spacecraft That Will Have a Panoramic View of the Sun

solar magnetic — Coronal loops in the Sun's atmosphere as viewed in ultraviolet "light." Courtesy UCAR.

The Sun is active, dynamic, and occasionally violent. Unfortunately our view of the Sun is limited to a small handful of orbiting satellites and ground-based observatories. The Solar Ring is new proposal that hopes to radically change that picture by launching a trio of satellites around the Sun to give continuous, 360° panoramic images in real time. The observatory could revolutionize our understanding of our parent star.

November 7, 2022November 7, 2022 by Evan Gough

The Perfect Tidal Tail Connects These two Galaxies Seen by Hubble

This image from the NASA/ESA Hubble Space Telescope shows two of the galaxies in the galactic triplet Arp 248. Image Credit: ESA/Hubble & NASA, Dark Energy Survey/Department of Energy/Fermilab Cosmic Physics Center/Dark Energy Camera/Cerro Tololo Inter-American Observatory/NOIRLab/National Science Foundation/AURA Astronomy; J. Dalcanton

Sometimes it’s tempting to imagine a supernatural hand behind the arrangement of celestial bodies. But the Universe is big, huge even, and nature’s flow presents many fascinations.

So it is with the galactic triplet Arp 248, an arrangement of interacting galaxies that’s both visually and scientifically fascinating.

November 7, 2022February 7, 2023 by Matt Williams

Hubble saw Multiple Light Echoes Reflecting off Rings of Dust From a Supernova Explosion

Artist view of a supernova explosion. Credit: NASA

When stars reach the end of their life cycle, they experience gravitational collapse at their centers and explode in a fiery burst (a supernova). This causes them to shed their outer layers and sends an intense burst of light and high-energy short-wavelength radiation (like X-rays and gamma-rays) out in all directions. This process also creates cosmic rays, which consist of protons and atomic nuclei that are accelerated to close to the speed of light. And on rare occasions, supernovae can also create “light echoes,” rings of light that spread out from the site of the original explosion.

These echoes will appear months to years after the supernova occurs as light from the explosion interacts with the layers of dust in the vicinity. Using the Hubble Space Telescope (HST), an international team of astronomers was able to document the emergence and evolution of multiple light echoes (LEs). The team traced these echoes to a stripped-envelope supernova (SN 2016adj) located in the central dust lane of Centaurus A, a galaxy located 10 to 16 million light-years away in the constellation of Centaurus.