Space and astronomy news
Astronomers have studied the star formation process for decades. As we get more and more capable telescopes, the intricate details of one of nature’s most fascinating processes become clearer. The earliest stages of star formation happen inside a dense veil of gas and dust that stymies our observations.
But the James Webb Space Telescope sees right through the veil in its images of nearby galaxies.
Continue reading “Galaxies Aren’t Just Stars. They’re Intricate Networks of Gas and Dust”
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”
In the 1970s, astronomers discovered that the persistent radio source at the center of our galaxy was a supermassive black hole (SMBH). Today, this gravitational behemoth is known as Sagittarius A* and has a mass roughly 4 million times that of the Sun. Since then, surveys have shown that SMBHs reside at the center of most massive galaxies and play a vital role in star formation and galactic evolution. In addition, the way these black holes consume gas and dust causes their respective galaxies to emit a tremendous amount of radiation from their Galactic Centers.
These are what astronomers refer to as Active Galactic Nuclei (AGN), or quasars, which can become so bright that they temporarily outshine all the stars in their disks. In fact, AGNs are the most powerful compact steady sources of energy in the Universe, which is why astronomers are always trying to get a closer look at them. For instance, a new study led by the University of California, Santa Cruz (UCSC) indicates that scientists have substantially underestimated the amount of energy emitted by AGN by not recognizing the extent to which their light is dimmed by dust.
Continue reading “Dust is Hiding how Powerful Quasars Really are”
Using telescopes that study the sky in the microwave part of the electromagnetic spectrum, astronomers have successfully mapped the structure of the magnetic field of the Milky Way galaxy. While magnetic fields are difficult to measure in space, an international team of astronomers used the Teide Observatory on Tenerife in the Canary Islands to conduct 10 years of observations.
Continue reading “You’re Looking at a Map of the Milky Way’s Magnetic Field”
For the first time this week, photos from the James Webb Space Telescope (JWST) revealed that stellar bars were present in some galaxies as far back as 11 billion years ago. Stellar bars are a defining feature of about two-thirds of all spiral galaxies in the Universe, including our own Milky Way. The discovery has implications for astronomers’ understanding of galactic evolution, indicating that bars form very quickly and may persist for much of a galaxy’s lifespan, influencing its shape and structure.
Continue reading “New JWST Image Shows That Grand Spiral Galaxies had Already Formed 11 Billion Years ago”
Although dark matter is a central part of the standard cosmological model, it’s not without its issues. There continue to be nagging mysteries about the stuff, not the least of which is the fact that scientists have found no direct particle evidence of it. Despite numerous searches, we have yet to detect dark matter particles. So some astronomers favor an alternative, such as Modified Newtonian Dynamics (MoND) or modified gravity model. And a new study of galactic rotation seems to support them.
Continue reading “New Measurements of Galaxy Rotation Lean Towards Modified Gravity as an Explanation for Dark Matter”
Studying the large-scale structure of our galaxy isn’t easy. We don’t have a clear view of the Milky Way’s shape and features like we do of other galaxies, largely because we live within it. But we do have some advantages. From within, we’re able to carry out close-up surveys of the Milky Way’s stellar population and its chemical compositions. That gives researchers the tools they need to compare our own galaxy to the many millions of others in the Universe.
This week, an international team of researchers from the USA, UK, and Chile released a paper that does just that. They dug through a catalogue of ten thousand galaxies produced by the Sloan Digital Sky Survey, searching for galaxies with similar attributes to our own.
They discovered that the Milky Way has twins – many of them – but just as many that are only superficially similar, with fundamental differences buried in the data. What they discovered has implications for the future evolution of our own galaxy.
Continue reading “Is the Milky Way… Normal?”
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.
Continue reading “A Star was Blocking a Galaxy, but Now it’s Moved Enough That Astronomers can Finally Examine What it Was Hiding”
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.
Continue reading “Gaze Slack-jawed at the Haunting Beauty of Galaxy NGC 1566, Captured by JWST, Processed by Judy Schmidt”
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.
Continue reading “The Perfect Tidal Tail Connects These two Galaxies Seen by Hubble”