galaxies Archives

December 12, 2022December 12, 2022 by Evan Gough

A Black Hole has been Burping for 100 Million Years

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

Black holes are gluttonous behemoths that lurk in the center of galaxies. Almost everybody knows that nothing can escape them, not even light. So when anything made of simple matter gets too close, whether a planet, a star or a gas cloud, it’s doomed.

But the black hole doesn’t eat it at once. It plays with its food like a fussy kid. Sometimes, it spews out light.

When the black hole is not only at the center of a galaxy but the center of a cluster of galaxies, these burps and jets carve massive cavities out of the hot gas at the center of the cluster called radio bubbles.

December 7, 2022December 7, 2022 by Evan Gough

A Star was Blocking a Galaxy, but Now it’s Moved Enough That Astronomers can Finally Examine What it Was Hiding

NASA's Hubble Space Telescope captured a detailed image of the tiny galaxy HIPASS J1131–31, nicknamed the "Peekaboo Galaxy." It's more like an ancient galaxy from the Universe's early days than a modern galaxy. Image Credit: NASA, ESA, and Igor Karachentsev (SAO RAS); Image Processing: Alyssa Pagan (STScI)

One of the biggest puzzles in astronomy, and one of the hardest ones to solve, concerns the formation and evolution of galaxies. What did the first ones look like? How have they grown so massive?

A tiny galaxy only 20 million light-years away might be a piece of the puzzle.

December 3, 2022December 3, 2022 by Evan Gough

How Do Stars Get Kicked Out of Globular Clusters?

Hubble image of Messier 54, a globular cluster located in the Sagittarius Dwarf Galaxy. Credit: ESA/Hubble & NASA

Globular clusters are densely-packed collections of stars bound together gravitationally in roughly-shaped spheres. They contain hundreds of thousands of stars. Some might contain millions of stars.

Sometimes globular clusters (GCs) kick stars out of their gravitational group. How does that work?

November 29, 2022November 29, 2022 by Evan Gough

Astronomers Detect the Faint Glow of Stars in Between Galaxies

Light 'between' the groups of galaxies – the "intra-group light" – however dim, is radiated from stars stripped from their home galaxy. Image Credit: MARTÍNEZ-LOMBILLA ET AL./UNSW SYDNEY

Not all stars are members of galaxies. Some stars exist in the space between galaxies, though they didn’t form there. They’re called intra-group stars, and astronomers study them by observing their light, called intra-group light (IGL.)

They’re challenging to observe because their light is extremely faint and overpowered by the light of nearby galaxies.

November 28, 2022November 28, 2022 by Nancy Atkinson

Gaze Slack-jawed at the Haunting Beauty of Galaxy NGC 1566, Captured by JWST, Processed by Judy Schmidt

NGC 1566, as seen by the James Webb Space Telescope's Mid-Infrared Instrument. Credit: NASA/ESA/CSA/Judy Schmidt.

Here’s an absolutely stunning new view from the James Webb Space Telescope of a dusty spiral galaxy, NGC 1566. Amateur (but expert!) image editor Judy Schmidt took the raw data from JWST’s Mid-Infrared Instrument (MIRI) and teased out this eerie, spider-web-like view of this distant galaxy. The swirling and symmetrical arms are so full of dust that not many stars are visible.

November 18, 2022November 18, 2022 by Evan Gough

Andromeda Contains the Remnants of a Recent “Feeding Event”

NASA Spitzer Space Telescope's infrared image of the Andromeda galaxy. Credit: NASA/JPL-Caltech/Univ. of Ariz.

There’s a growing body of evidence that galaxies grow large by merging with other galaxies. Telescopes like the Hubble have captured dozens of interacting galaxies, including well-known ones like Arp 248. The Andromeda galaxy is the nearest large galaxy to the Milky Way, and a new study shows that our neighbour has consumed other galaxies in two distinct epochs.

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.

October 30, 2022October 30, 2022 by Carolyn Collins Petersen

Too Many Supernovae Can Slow Star Formation in a Galaxy

star formation regions in M33 are disrupted by cosmic-ray driven winds — Artist's illustration of cosmic ray-driven winds (blue and green) superimposed on a visible-light image of the Triangulum galaxy M33 (red and white) observed with VLT Survey Telescope at ESO’s Paranal Observatory in Chile. Credit: Institute for Research in Fundamental Sciences- IPM & European Southern Observatory (ESO)

Interstellar winds are powerful agents of change. For one thing, they can interrupt or shut down the process of star birth completely. That’s what a team of astronomers using the Karl Jansky Very Large Array in New Mexico found when they studied the galaxy M33. They also learned that speedy cosmic rays play a huge role in pushing those winds across interstellar space.

October 28, 2022October 28, 2022 by Brian Koberlein

JWST Sees the Same Galaxy From Three Different Angles Thanks to a Gravitational Lens

This illustration shows how gravitational lensing works. The gravity of a large galaxy cluster is so strong, it bends, brightens and distorts the light of distant galaxies behind it. The scale has been greatly exaggerated; in reality, the distant galaxy is much further away and much smaller. Credit: NASA, ESA, L. Calcada

One of the great tragedies of the night sky is that we will never travel to much of what we see. We may eventually travel to nearby stars, and even distant reaches of our galaxy, but the limits of light speed and cosmic expansion make it impossible for us to travel beyond our local group. So we can only observe distant galaxies, and we can only observe them from our home in the universe. You might think that means we can only see one face of those galaxies, but thanks to the James Webb Space Telescope that isn’t entirely true.

October 25, 2022October 25, 2022 by Nancy Atkinson

Webb and Hubble Peer Into the Wreckage of a Galactic Collision

This image from the NASA/ESA/CSA James Webb Space Telescope depicts IC 1623, an entwined pair of interacting galaxies which lies around 270 million light-years from Earth in the constellation Cetus. Credit: ESA/Webb, NASA & CSA, L. Armus & A. Evans; CC BY 4.0 Acknowledgement: R. Colombari.

Earlier this month we asked, what could be better than a pair of galaxies observed by a pair of iconic space telescopes? Now, there is an exciting new answer. Even better than a pair of galaxies is a pair of galaxies that are colliding!

The Hubble Space Telescope and the James Webb Space Telescope have each taken a look at a pair of intertwined galaxies that are 270 million light-year away from Earth, together called IC 1623. Scientists say this galactic collision has ignited frenzied star formation called a starburst, creating new stars at a rate more than 20 times that of our Milky Way.