If we want to know what it’ll look like in about 4.5 billion years when our galaxy merges with Andromeda, we might take a look at ARP 220. ARP 220 is a pair of galaxies that are in the process of merging. The merging galaxies emit brilliant infrared light, and the James Webb Space Telescope captured that light in a vivid portrait.Continue reading “JWST Sees Merging Galaxies Releasing the Light of a Trillion Suns”
Astronomers know that galaxies grow over time through mergers with other galaxies. We can see it happening in our galaxy. The Milky Way is slowly absorbing the Large and Small Magellanic Clouds and the Sagittarius Dwarf Spheroidal Galaxy.
For the first time, astronomers have found evidence of an ancient mass migration of stars into another galaxy. They spotted over 7,000 stars in Andromeda (M31), our nearest neighbour, that merged into the galaxy about two billion years ago.Continue reading “Astronomers Uncover Mass Migration of Stars into Andromeda”
Humanity is in a back-and-forth relationship with nature. First, we thought we were at the center of everything, with the Sun and the entire cosmos rotating around our little planet. We eventually realized that wasn’t true. Over the centuries, we’ve found that though Earth and life might be rare, our Sun is pretty normal, our Solar System is relatively non-descript, and even our galaxy is one of the billions of spiral galaxies, a type that makes up 60% of the galaxies in the Universe.
But the Illustris TNG simulation shows that the Milky Way is special.Continue reading “According to Simulations, the Milky Way is One in a Million”
The death of a star is one of the most dramatic natural events in the Universe. Some stars die in dramatic supernova explosions, leaving nebulae behind as shimmering remnants of their former splendour. Some simply wither away as their hydrogen runs out, billowing into a red giant as they do so.
But others are consumed by behemoth black holes, and as they’re destroyed, the black hole’s powerful gravity tears the star apart and draws its gas into a donut-shaped ring around the black hole.Continue reading “The Donut That Used To Be a Star”
When the James Webb Space Telescope lifted off from Earth on Christmas Day in 2021, it carried a lot of expectations with it. One of its scientific goals is to seek the light from the first galaxies in the Universe and to study how galaxies form and evolve.
A new paper shows that the JWST is doing just that and has found a link between the first galaxies and rare galaxies in our backyard that astronomers call “Green Pea” galaxies.Continue reading “The James Webb Links Modern Green Pea Galaxies to Ancient Galaxies in the Cosmic Dawn”
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.Continue reading “Astronomers Detect the Faint Glow of Stars in Between Galaxies”
When the James Webb Space Telescope (JWST) launched, one of its jobs was studying galactic formation and evolution. When we look around the Universe, today’s galaxies take the shape of grand spirals like the Whirlpool galaxy and giant ellipticals like M60. But galaxies didn’t always look like this.
We don’t see these shapes when we look at the most distant and most ancient galaxies. Early galaxies are lumpy and misshapen and lack the structure of modern galaxies.
A new study based on JSWT observations looks at organic molecules near galactic centers. The researchers say observing these molecules can teach us a lot about galactic evolution.Continue reading “Webb Sees Organic Molecules in the Hearts of Galaxies, Surprisingly Close to Active Supermassive Black Holes”
A recent study looked at stellar streams hidden in Gaia data, to uncover evidence of an ancient remnant dubbed Pontus.
Our home galaxy the Milky Way is a monster with a ravenous past. In its estimated 12 billion years of existence, our galaxy has swallowed smaller satellite galaxies whole, with collisions resulting in massive rounds of star formation. We see threads of these remnant mergers as streams of stars and clusters, strung out around the Milky Way.Continue reading “Gaia Finds Ancient Satellite Galaxy Pontus Embedded in Milky Way”
As we learn more about the cosmos, it’s interesting how some of the greatest discoveries continue to happen close to home. This is expected to continue well into the future, where observations of Cosmic Dawn and distant galaxies will take place alongside surveys of the outer Solar System and our galaxy. In this latter respect, the ESA’s Gaia observatory will continue to play a vital role. As an astrometry mission, Gaia has been to determine the proper position and radial velocity of over a billion stars to create a three-dimensional map of the Milky Way.
Using data from Gaia’s third early Data Release (eDR3) and Legacy Survey data – from the Sloan Digital Sky Survey (SDSS) – an international team of astronomers created a new map of the Milky Way’s outer disk. In the process, they discovered evidence of structures in this region that include the remnants of fossil spiral arms. This discovery will shed new light on the formation and history of the Milky Way and may lead to a breakthrough in our understanding of galactic evolution.Continue reading “A Detailed Scan of the Milky Way Finds Possible “Fossil” Spiral Arms”
Galaxies that formed within the first few billion years after the Big Bang should have lived long, healthy lives. After all, they were born with rich supplies of cold hydrogen gas, exactly the fuel needed to continue star formation. But new observations have revealed “quenched” galaxies that have shut off star formation. And astronomers have no idea why.Continue reading “Early Massive Galaxies ran out of gas, Shutting Down Their Star Formation”