Paul M. Sutter, Author at Universe Today

February 2, 2021February 1, 2021 by Paul M. Sutter

Astronomers are Starting to Understand the Quasar Lifecycle

Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

Supermassive black holes have a complicated lifecycle. Sometimes they’re “on”, blasting out tremendous amounts of energy, and sometimes they’re “off’, where they sleep like dragons in their caves. By comparing the proportion of high-energy to low-energy waves emitted by quasars, astronomers are beginning to pin down how many black holes are sleeping, and when they’re likely to wake back up.

February 1, 2021February 1, 2021 by Paul M. Sutter

Galaxy Mergers can Boost Star Formation, and it can Also Shut it Down

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here — known as NGC 3921 — is one of these systems. NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger. The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.

Galaxy mergers are beautiful sights, but ultimately deadly. In the midst of the collision, the combined galaxy will shine brighter than it ever has before. But that glory comes with a price: all those new stars use up all the available fuel, and star formation grinds to a halt.

February 1, 2021February 1, 2021 by Paul M. Sutter

White Dwarf Atmospheres Might Contain the Pulverized Crusts of Their Dead Planets

Illustration of the internal layers of a white dwarf star. Credit: University of Warwick/Mark Garlick

Astronomers have developed a new technique to search for exoplanets – by looking for their crushed up bones in the atmospheres of white dwarfs. And it’s working.

January 27, 2021January 25, 2021 by Paul M. Sutter

Galileo’s Probe Discovered a Mystery at Jupiter, Juno Finally Helped Solve it

A multitude of magnificent, swirling clouds in Jupiter's dynamic North North Temperate Belt is captured in this image from NASA's Juno spacecraft. Appearing in the scene are several bright-white "pop-up" clouds as well as an anticyclonic storm, known as a white oval. Image Credit: Enhanced Image by Gerald Eichstädt and Sean Doran (CC BY-NC-SA)/NASA/JPL-Caltech/SwRI/MSSS

In 1995, NASA’s Galileo mission dropped a probe into the atmosphere of Jupiter and found it to be far drier than expected. In 2020, NASA’s follow-up mission Juno explained the mystery: it involves mushballs.

January 26, 2021January 25, 2021 by Paul M. Sutter

You Know it’s Spring on Mars When the Carbon Dioxide is Starting to Sublimate

The first signs of Spring in the northern polar ice cap on Mars: fans of dust launched by sublimating gas. Credit: NASA/JPL/UArizona

The northern hemisphere of Mars is beginning to thaw from winter. But for the red planet, that doesn’t mean that birds will sing and flowers will bloom. It means that the carbon dioxide will sublimate. It’s still beautiful though.

January 26, 2021February 6, 2021 by Paul M. Sutter

Away From the Light Pollution of the Inner Solar System, New Horizons was Able to see how Dark the Universe Really is

NASA's New Horizons spacecraft (when it still lived on the Earth).

Just how dark is the universe, anyway? It’s a pretty hard thing to measure when we’re sitting this close to the sun. But NASA’s New Horizons probe is so far away that the images it takes of the distant universe are able to deliver the most accurate measurement ever of the universe’s diffuse background light.

January 25, 2021January 25, 2021 by Paul M. Sutter

Astronomers Hoped to see Evidence of Dark Matter Particles Inside Betelgeuse. No Luck

An artist's impression of Betelgeuse. Its surface is covered by large star spots, which reduce its brightness. During their pulsations, such stars regularly release gas into their surroundings, which condenses into dust. Image Credit: MPIA graphics department

Axions are a hypothetical particle that might explain the existence of dark matter. But it might occasionally interact with normal matter, especially in the cores of stars. A team of physicists have searched for evidence of axions in Betelgeuse and come up with nothing. It doesn’t mean that the axion doesn’t exist, but it does mean that it will be harder to find.

January 11, 2021January 11, 2021 by Paul M. Sutter

Astronomers see Swirling Weather on the Closest Brown Dwarf

An artist's conception of a brown dwarf. A new study identifies CK Vulpeculae as the remnant of a collison between a brown dwarf and a white dwarf. Image: By NASA/JPL-Caltech (http://planetquest.jpl.nasa.gov/image/114) [Public domain], via Wikimedia Commons — An artist's conception of a brown dwarf. Brown dwarfs are more massive than Jupiter but less massive than the smallest main sequence stars. Image: By NASA/JPL-Caltech (http://planetquest.jpl.nasa.gov/image/114) [Public domain], via Wikimedia Commons

Brown dwarfs are the weird not-planets but not-stars in the universe, and astronomers have wondered for decades if their atmospheres are striped like Jupiter’s, or splotchy like the sun’s. A team of astronomers based at the University of Arizona used NASA’s TESS Observatory to find the answer: if you saw a brown dwarf for yourself, it would look more like a giant planet than a star.

January 11, 2021January 11, 2021 by Paul M. Sutter

This is the Fireworks Galaxy. It’s had ten Supernovae in the Last Century Alone

NGC 6946, also known as the Fireworks Galaxy due to the stupendous number of active supernovae. Image credit: ESA/Hubble & NASA, A. Leroy, K.S. Long

Say hello to NGC 6946, otherwise known as the Fireworks Galaxy. This little galaxy is the most prolific producer of supernovae in the known universe, popping off those incredible explosions roughly once a decade. It’s secret? An incredibly high rate of star formation.

January 6, 2021January 5, 2021 by Paul M. Sutter

There Should be a few Supernovae in the Milky Way Every Century, but we’ve Only Seen 5 in the Last 1000 Years. Why?

This image of the supernova remnant SN 1987A was taken by the NASA/ESA Hubble Space Telescope in January 2017 using its Wide Field Camera 3 (WFC3). Since its launch in 1990 Hubble has observed the expanding dust cloud of SN 1987A several times has helped astronomers get a better understanding of these cosmic explosions. Supernova 1987A is located in the centre of the image amidst a backdrop of stars. The bright ring around the central region of the exploded star is material ejected by the star about 20 000 years before the actual explosion took place. The supernova is surrounded by gaseous clouds. The clouds’ red colour represents the glow of hydrogen gas. Image Credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) and P. Challis (Harvard-Smithsonian Center for Astrophysics)

Our galaxy hosts supernovae explosions a few times every century, and yet it’s been hundreds of years since the last observable one. New research explains why: it’s a combination of dust, distance, and dumb luck.