Astronomers Have Tracked Down the Source of High Energy Cosmic Rays to Regions Within the Milky Way Itself

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)
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)

Using a new observatory, a team of Chinese astronomers have found over a dozen sources of ultra-high energy cosmic rays. And those sources aren’t from some distant, exotic corner of the cosmos. They come from our own backyard.

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New Mosaic Shows the Galactic Core From Opposite Sides of the Electromagnetic Spectrum

Credit: X-ray: NASA/CXC/UMass/Q.D. Wang; Radio: NRF/SARAO/MeerKAT)

The core of the Milky Way Galaxy (aka. Galactic Center), the region around which the rest of the galaxy revolves, is a strange and mysterious place. It is here that the Supermassive Black Hole (SMBH) that powers the compact radio source known as Sagittarius A* is located. It is also the most compact region in the galaxy, with an estimated 10 million stars within 3.26 light-years of the Galactic Center.

Using data from Chandra X-ray Observatory and the MeerKAT radio telescope, NASA and the National Research Foundation (NSF) of South Africa created a mosaic of the center of the Milky Way. Combining images taken in the x-ray and radio wavelengths, the resulting panoramic image manages to capture the filaments of super-heated gas and magnetic fields that (when visualized) shows the complex web of energy at the center of our galaxy.

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One of the Oldest Stars in the Galaxy has a Planet. Rocky Planets Were Forming at Nearly the Beginning of the Universe

Artist's rendition of TOI-561, one of the oldest, most metal-poor planetary systems discovered yet in the Milky Way galaxy. This 10 billion-year-old system has a hot, rocky exoplanet (center) that's one and a half times the size of Earth as well as two gas planets (to the left of the rocky planet) that are about twice as large as Earth. Credit: W. M. Keck Observatory/Adam Makarenko

Would it be surprising to find a rocky planet that dates back to the very early Universe? It should be. The early Universe lacked the heavier elements necessary to form rocky planets.

But astronomers have found one, right here in the Milky Way.

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You Can Actually See the Milky Way’s Wave When You Map Its Stars

Spiral galaxies are one of the most commonly known types of galaxy.  Most people think of them as large round disks, and know that our Milky Way is counted among their number.  What most people don’t realize is that many spiral galaxies have a type of warping effect that, when you look at them edge on, can make it seem like they are forming a wave.  Now scientists, led by Xinlun Chen at the University of Virginia, have studied millions of stars in the Milky Way and begun to develop a picture of a “wave” passing through our own galaxy.

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Astronomers Discover Hundreds of High-Velocity Stars, Many on Their Way Out of the Milky Way

Since discovering the first one in 2005, astronomers have found hundreds of stars that travel fast enough that they could escape the Milky Way as HVSs. Image Credit: NAOC/Kong Xiao

Within our galaxy, there are thousands of stars that orbit the center of the Milky Way at high velocities. On occasion, some of them pick up so much speed that they break free of our galaxy and become intergalactic objects. Because of the extreme dynamical and astrophysical processes involved, astronomers are most interested in studying these stars – especially those that are able to achieve escape velocity and leave our galaxy.

However, an international team of astronomers led from the National Astronomical Observatories of China (NAOC) recently announced the discovery of 591 high-velocity stars. Based on data provided by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the ESA’s Gaia Observatory, they indicated that 43 of these stars are fast enough to escape the Milky Way someday.

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A new measurement puts the Sun 2,000 light-years closer to the center of the Milky Way

Standing beside the Milky Way. Drowming out the night sky blocks us off from nature, and that's not good for humans. Credit: P. Horálek/ESO

Where are we? Cosmically, we’re in our home galaxy, typically known as the Milky Way. The center of our galaxy is marked by a supermassive black hole, which the Sun orbits at a distance of about 30,000 light-years. The official distance, set by the International Astronomical Union in 1985, is 27,700 light-years. But a new study as confirmed we are actually a bit closer to the black hole.

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A third of the stars in the Milky Way came from a single merger 10 billion years ago

This artist’s impression shows how the Milky Way galaxy would look seen from almost edge on and from a very different perspective than we get from the Earth. The central bulge shows up as a peanut shaped glowing ball of stars and the spiral arms and their associated dust clouds form a narrow band. Image Credit: By ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt - http://www.eso.org/public/images/eso1339a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=28256788

Ten billion years ago the young Milky Way survived a titanic merger with a neighboring galaxy, eventually consuming the whole thing. Now, remnants of that fossil galaxy still swim in our galaxy’s core – and astronomers have discovered that almost a third of the Milky Way’s current population came from that dismantled rival.

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Some of the Milky Way’s oldest stars aren’t where they’re expected to be

Representation of the orbit of the star 232121.57-160505.4. Credit: Cordoni, et al

One of the ways we categorize stars is by their metallicity. That is the fraction of heavier elements a star has compared to hydrogen and helium. It’s a useful metric because the metallicity of a star is a good measure of its age.

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The Spherical Structure at the Core of the Milky Way Formed in a Single Burst of Star Formation

This artist’s impression shows how the Milky Way galaxy would look seen from almost edge on and from a very different perspective than we get from the Earth. The central bulge shows up as a peanut shaped glowing ball of stars and the spiral arms and their associated dust clouds form a narrow band. Image Credit: By ESO/NASA/JPL-Caltech/M. Kornmesser/R. Hurt - http://www.eso.org/public/images/eso1339a/, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=28256788

Like other spiral galaxies, the Milky Way has a bulging sphere of stars in its center. It’s called “The Bulge,” and it’s roughly 10,000 light-years in radius. Astronomers have debated the bulge’s origins, with some research showing that multiple episodes of star formation created it.

But a new survey with the NOIRLab’s Dark Energy Camera suggests that one single epic burst of star formation created the bulge over 10 billion years ago.

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Astronomers Map Out the Raw Material for New Star Formation in the Milky Way

Accroding to new research, the Milky Way may still bear the marks of "ancient impacts". Credit: NASA/Serge Brunier

A team of researchers has discovered a complex network of filamentary structures in the Milky Way. The structures are made of atomic hydrogen gas. And we all know that stars are made mostly of hydrogen gas.

Not only is all that hydrogen potential future star-stuff, the team found that its filamentary structure is also a historical imprint of some of the goings-on in the Milky Way.

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