Our galaxy’s stellar halo is giving astronomers some new food for thought. It turns out everyone thought the halo was spherical. But, it’s not. That’s news to everyone who said it was spherical. According to a new measurement done by a team at Harvard-Smithsonian Center for Astrophysics, it has a tilted, oblong football shape. This all tells astronomers an interesting tale about our galaxy’s ancient history.Continue reading “The Milky Way’s Stellar Halo Isn’t a Sphere After All”
A Dwarf Galaxy Passed Close to the Milky Way and Left Ripples in its Wake
When you imagine the collision of galaxies, you probably think of something violent and transformational. Spiral arms ripped apart, stars colliding, cats and dogs living together, mass hysteria. The reality is much less dramatic. As a recent study shows, our galaxy is in a collision right now.Continue reading “A Dwarf Galaxy Passed Close to the Milky Way and Left Ripples in its Wake”
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Star Formation in the Center of the Milky Way Started at the Core and Then Worked its way out
One of the biggest questions facing astronomers today concerns star formation and its role in the evolution of galaxies. In particular, astronomers are curious whether the process began in the central regions of galaxies, where stars are more tightly bound. Previous observations have shown that numerous galaxies experienced intense periods of star formation in their centers roughly one billion years after the Big Bang. For some time, astronomers have wanted to conduct similar observations of the Milky Way’s Galactic Center to study rapid star formation more closely.
Unfortunately, it has been very difficult for astronomers to study the center of the Milky Way because of how bright and densely packed the region is, which makes it difficult to discern individual stars and clusters. Thanks to a new analysis of a high-resolution infrared survey, a team of astronomers has created the first reconstruction of the star formation history in the Galactic Center. According to their findings, most young stars in this region formed in loose stellar associations that dispersed outwards to fill the Galactic Disk over the course of many eons (as opposed to tightly-knit massive clusters).Continue reading “Star Formation in the Center of the Milky Way Started at the Core and Then Worked its way out”
Is This the Future of the Milky Way?
Take a good look at the latest image provided by the Hubble Space Telescope. It shows a huge elliptical galaxy called NGC 474 that lies about 100 million light-years away from us. At about two and a half times larger than our Milky Way Galaxy, it’s really a behemoth. Notice its strange structure—mostly featureless and nearly round, but with layered shells wrapped around the central core. Astronomers want to know what caused these shells. The answer might be in what this galaxy represents: a vision of the future Milky Way and the Andromeda Galaxy.Continue reading “Is This the Future of the Milky Way?”
Slimmed Down Red Giants Had Their Mass Stolen By a Companion Star
Millions of stars that can grow up to 620 million miles in diameter, known as ‘red giants,’ exist in our galaxy, but it has been speculated for a while that there are some that are possibly much smaller. Now a team of astronomers at the University of Sydney have discovered several in this category and have published their findings in the journal Nature Astronomy.
Continue reading “Slimmed Down Red Giants Had Their Mass Stolen By a Companion Star”
“It’s like finding Wally… we were extremely lucky to find about 40 slimmer red giants, hidden in a sea of normal ones. The slimmer red giants are either smaller in size or less massive than normal red giants.”PhD candidate Mr Yaguang Li from the University of Sydney, as quoted from the source article.
The Milky Way has an Inner Ring, Just Outside the Core
In the past century, astronomers have learned a great deal about the cosmos and our place in it. From discovering that the Universe is in a constant state of expansion to the discovery of the Cosmic Microwave Background (CMB) and the Big Bang cosmological model, our perception of the cosmos has expanded immensely. And yet, many of the most profound astronomical discoveries still occur within our cosmic backyard – the Milky Way Galaxy.
Compared to other galaxies, which astronomers can resolve with relative ease, the structure and size of the Milky Way have been the subject of ongoing discovery. The most recent comes from the Max Planck Institute for Extraterrestrial Physics (MPE), where scientists have found a previously undiscovered inner ring of metal-rich stars just outside the Galactic Bar. The existence of this ring has revealed new insights into star formation in this region of the galaxy during its early history.Continue reading “The Milky Way has an Inner Ring, Just Outside the Core”
Part of the Milky Way Is Much Older Than Previously Believed
The Milky Way is older than astronomers thought, or part of it is. A newly-published study shows that part of the disk is two billion years older than we thought. The region, called the thick disk, started forming only 0.8 billion years after the Big Bang.Continue reading “Part of the Milky Way Is Much Older Than Previously Believed”
Astronomers Scan the Center of the Milky Way for Any Sign of Intelligent Civilizations. Nothing but Silence.
Are there civilizations somewhere else in the Universe? Somewhere else in the Milky Way? That’s one of our overarching questions, and an answer in the affirmative would be profound.
Humanity’s pursued the Search for Extraterrestrial Intelligence (SETI) in one form or another since shortly after the advent of radio waves in the early 20th century. Efforts have waxed and waned over the decades, but the search has never been completely abandoned.
The search detected transient hints in the form of unexplained radio waves in the past, but nothing that comprises reliable evidence. Now a new search for technosignatures in the Milky Way’s center has turned up nothing.Continue reading “Astronomers Scan the Center of the Milky Way for Any Sign of Intelligent Civilizations. Nothing but Silence.”
Nearby Supernovae Exploded Just a few Million Years Ago, Leading to a Wave of Star Formation Around the Sun
The Sun isn’t the only star in this galactic neighbourhood. Other stars also call this neighbourhood home. But what’s the neighbourhood’s history? What triggered the birth of all those stars?
A team of astronomers say they’ve pieced the history together and identified the trigger: a series of supernovae explosions that began about 14 million years ago.Continue reading “Nearby Supernovae Exploded Just a few Million Years Ago, Leading to a Wave of Star Formation Around the Sun”
The Milky Way’s Most Recent Meal was a Galaxy it Gobbled up 8-10 Billion Years ago
A central aspect of galactic evolution is that they must eat or be eaten. Dark energy strives to push galaxies apart, but gravity tries to pull them together. As a result, galaxies tend to form into local groups. As these superclusters of galaxies become more isolated due to cosmic expansion, they gravitationally turn on each other, and in time the largest galaxies of the group will consume the smaller ones. The Milky Way is one of the larger galaxies in our local group, and so it has consumed smaller galaxies in the past. But piecing together the history of these galactic meals is a real challenge.Continue reading “The Milky Way’s Most Recent Meal was a Galaxy it Gobbled up 8-10 Billion Years ago”