Carolyn Collins Petersen, Author at Universe Today

January 16, 2024January 16, 2024 by Carolyn Collins Petersen

A Primordial Dark Matter Galaxy Found Without Stars

An artistic concept of hydrogen gas observed in galaxy J0613+52. The colors indicate the rotational action of gas relative to us. Courtesy: STScI POSS-11, NSF/GBO/P. Vosteen.

There’s a galaxy out there without apparent stars but largely chock full of dark matter. What’s that you say? A galaxy without stars? Isn’t that an impossibility? Not necessarily, according to the astronomers who found it and are trying to explain why it appears starless. “What we do know is that it’s an incredibly gas-rich galaxy,” said Green Bank Observatory’s Karen O’Neil, an astronomer studying this primordial galactic object. “It’s not demonstrating star formation like we’d expect, probably because its gas is too diffuse.”

January 13, 2024January 13, 2024 by Carolyn Collins Petersen

Black Holes and Neutron Stars are Finally Linked to Supernovae

A star in a binary system dies in a catastrophic explosion. Such supernovae often result in neutron stars or black holes. Courtesy ESO/L. Calçada — This artist’s impression is based on the aftermath of a supernova explosion as seen by two teams of astronomers with both ESO’s Very Large Telescope (VLT) and ESO’s New Technology Telescope (NTT). The supernova observed, SN 2022jli, occurred when a massive star died in a fiery explosion, leaving behind a compact object — a neutron star or a black hole. This dying star, however, had a companion which was able to survive this violent event. The periodic interactions between the compact object and its companion left periodic signals in the data, which revealed that the supernova explosion had indeed resulted in a compact object.

Everybody knows that the explosive deaths of supermassive stars (called supernovae) lead to the creation of black holes or neutron stars, right? At least, that’s the evolutionary path that astronomers suggest happens. And, these compact objects exist throughout the Universe. But, no one’s ever seen the actual birth process of a neutron star or black hole in action before.

January 10, 2024January 10, 2024 by Carolyn Collins Petersen

Hubble Shows That a Fast Radio Burst Came From a Giant Group of Galaxies

A Hubble Space Telescope image of the host galaxy of an exceptionally powerful Fast Radio Burst, FRB20220610A. Hubble’s sensitivity and sharpness reveals a compact group of multiple galaxies that may be in the process of merging. Courtesy: NASA, ESA, STScI, Alexa Gordon (Northwestern University)

Way back when the cosmos was only five billion years old, a powerful explosion happened in a group of young galaxies halfway across the Universe. It sent out a blast of radiation from one member of that distant galaxy group.

January 10, 2024January 10, 2024 by Carolyn Collins Petersen

Another Example of a Fantastic Einstein Ring

The gravitationally lensed galaxy HerS J020941.1+001557 (red ring) has its imaged distorted by the gravitational effect of a foreground galaxy. Credit: ESA/Hubble & NASA, H. Nayyeri, L. Marchetti, J. Lowenthal; CC BY 4.0 — The gravitationally lensed galaxy HerS J020941.1+001557 (red Einstein ring) has its imaged distorted by the gravitational effect of a foreground galaxy. Credit: ESA/Hubble & NASA, H. Nayyeri, L. Marchetti, J. Lowenthal; CC BY 4.0

The most evocative astronomy images take us across space and time to stars and galaxies billions of light-years away. Nestled at the center of this one, taken by the Hubble Space Telescope, is a collection of three galaxies. They’re not all that close together, although they appear to be in this image. What’s fascinating about this image is that it’s a fine example of an Einstein gravitational ring—and its discovery was enabled by members of the public!

January 7, 2024January 7, 2024 by Carolyn Collins Petersen

Uranus and Neptune are Actually Pretty Much the Same Color

Scientists reprocessed Voyager 2 images to get the "true" colors of Uranus and Neptune. Turns out they're a pretty blueish-green. Courtesy NASA/Irwin, et al, Anton Pozdnyakov.

In the late 1980s, the Voyager 2 spacecraft snapped the “canonical” up-close images of Uranus and Neptune. In those views, Uranus was a pretty greenish-blue and Neptune appeared a deep azure color. It turns out that both planets are pretty close in color: a greenish-blue more akin to Uranus’s appearance.

January 5, 2024January 5, 2024 by Carolyn Collins Petersen

Hubble Watches an Exoplanet Atmosphere Change Over Three Years

An artist impression of Tylos, also known as WASP-121 b. It has a hot exoplanet atmosphere that seems to be changing over time. Courtesy: NASA, ESA, Q. Changeat et al., M. Zamani (ESA/Hubble)

If you want to know more about an exoplanet atmosphere, watch how it changes over time. That’s the mantra of a group of astronomers who just reported on conditions at Tylos, otherwise known as WASP-121 b.

December 31, 2023December 31, 2023 by Carolyn Collins Petersen

How a Small Town in Japan Fiercely Defends its Dark Skies

The arch of the Milky Way seen over Bisei Town in Japan. It prides itself on its dark skies, but faces scattered light pollution from other nearby municipalities. Courtesy DarkSky.Org.

Light pollution ruins dark skies. It’s a scourge that ground-based observatories have to deal with in one form or another. Scientists used a small observatory in Japan to measure what changed when a nearby town improved its lighting practices. They also noted the challenges it still faces.

December 29, 2023December 29, 2023 by Carolyn Collins Petersen

Organic Molecules Come from the Universe’s Cold Places

Asteroid Ryugu contains organic molecules called polycyclic aromatic hydrocarbons, thought to be chemical building blocks for life. Courtesy ISAS/JAXA — Asteroid Ryugu as seen by Japan's Hayabusa 2 spacecraft, which returned a sample of the ancient asteroid to Earth in 2020. Image Courtesy ISAS/JAXA

Life, as we all know, is based on chemistry. Prebiotic chemical building blocks existed on our planet for a long time before life arose. Astrobiology and cosmochemistry focus on the formation of those building blocks. They also look at the role each played in creating all the life forms we know today.

December 27, 2023December 27, 2023 by Carolyn Collins Petersen

JWST Sets a New Record, Sees Newly Forming Stars in the Triangulum Galaxy

Galaxy M33 (Triangulum Galaxy) as seen by Hubble Space Telescope. JWST was used recently to observe sites in its southern arm where newly forming stars (YSOs) appear to lie.

Our Milky Way bristles with giant molecular clouds birthing stars. Based on what we see here, astronomers assume that the process of star creation also goes on similarly in other galaxies. It makes sense since their stars have to form somehow. Now, thanks to JWST, astronomers have spotted baby stellar objects in a galaxy 2.7 million light-years away. That’s millions of light-years more distant than any previous observations of newly forming stars have reached.

December 21, 2023December 22, 2023 by Carolyn Collins Petersen

Should We Be Preparing for First Contact?

First Contact. It’s a topic guaranteed to inspire a mix of emotions in people. It’s also one of the most fascinating SF scenarios we can imagine. What will people do when “they” appear? Or when we find evidence of life elsewhere in the Universe? For answers, one suggestion is to turn to a discipline called “exosociology”.