Star Streams of Sagittarius Dwarf Galaxy
Credit: Amanda Smith, Institute of Astronomy, University of Cambridge
Artist’s concept of the four tails of the Sagittarius dwarf galaxy (orange clump on left of the image) orbiting the Milky Way. The bright yellow circle to the right of the Milky Way’s center is our sun (not to scale). We can see the Sagittarius galaxy’s star tails stretching across the sky.
Milky Way by Phil Hart
Cape Leveque Nightscapes with the Vixen Polarie by Mike Salwa
This name derives from its appearance as a dim “milky” glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.
A research team has discovered masses thought to be “seeds” that form and grow massive black holes at the center of the Milky Way Galaxy, about 30,000 light-years from our solar system in the direction of Sagittarius.
The Milky Way is the galaxy in which Earth is contained. This name derives from its appearance as a dim “milky” glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.
2. Artist’s conception of the spiral structure of the Milky Way with two major stellar arms and a bar.
3. Illustration of the two gigantic X-ray/gamma-ray bubbles (blue-violet) of the Milky Way (center).
4. A false-color infrared image of the core of the Milky Way Galaxy taken by NASA’s Spitzer Space Telescope. Older cool stars are blue, dust features lit up by large hot stars are shown in a reddish hue, and the bright white spot in the middle marks the site of Sagittarius A*, the super-massive black hole at the center of the Galaxy.
Majestic Milky Way
Credit: Phil McGrew
The Milky Way shines over McWay Falls south of Big Sur, Calif. Photographer Phil McGrew pulled an “all-nighter” to get this shot.
Ghosts of Milky Way’s Powerful Past Revealed
In the image: This artist’s conception shows an edge-on view of the Milky Way galaxy. Newly discovered gamma-ray jets (pink) extend for 27,000 light-years above and below the galactic plane, and are tilted at an angle of 15 degrees. Previously known gamma-ray bubbles are shown in purple. The bubbles and jets suggest that our galactic center was much more active in the past than it is today.
Today the Milky Way Galaxy is a relatively quiet place. Our galaxy has grown up, and intense activity seen in other galaxies is a thing of our past. But scientists have long assumed the past was more hectic. A new study finds ghosts of past activity in the form of twin jets spat into space from the Milky Way’s central black hole.
Unlike our quiescent galaxy, active galaxies have cores that glow brightly, powered by supermassive black holes swallowing material and exciting the gas and dust around them to grow brightly in many wavelengths, from visible light to X-rays and gamma rays. Active galaxies also often shoot twin jets in opposite directions — beams of material thought to be directed by intense magnetic energy.
The new evidence of ghostly gamma-ray beams suggests that the Milky Way’s central black hole was much more active in the past.
“These faint jets are a ghost or after-image of what existed a million years ago,” said Meng Su, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), and lead author of a new paper in the Astrophysical Journal. “They strengthen the case for an active galactic nucleus in the Milky Way’s relatively recent past.”
The Milky Way over Yosemite Valley
From Glacier Point at the right, across Half Dome at center and ending at Royal Arches at the left, the path of the Milky Way is stunning even under lighting conditions that illuminate the valley walls.
The Milky Way and Perseid meteor shower light up the night sky
Photograph by Christoph Malin, TWAN
The Milky Way and the setting moon shine together in the night sky over La Palma, part of the Spanish Canary Islands, in a newly released picture taken last August.
The stitched panorama also shows the golden glow of city lights as well as the silhouette of Italy’s Telescopio Nazionale Galileo, one of many observatories perched on La Palma’s volcanic peaks. (Watch a time-lapse of the night sky shot from La Palma.)