APOD: Dust and the NGC 7771 Group (2010 Jan 21)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 5314
Joined: Fri Dec 04, 2009 3:27 am

APOD: Dust and the NGC 7771 Group (2010 Jan 21)

Post by APOD Robot » Thu Jan 21, 2010 4:55 am

Image Dust and the NGC 7771 Group

Explanation: Galaxies of the NGC 7771 Group are featured in this intriguing skyscape. Some 200 million light-years distant toward the constellation Pegasus, NGC 7771 is the large, edge-on spiral near center, about 75,000 light-years across, with two smaller galaxies just below it. Large spiral NGC 7769 is seen face-on to the right. Galaxies of the NGC 7771 group are interacting, making repeated close passages that will ultimately result in galaxy-galaxy mergers on a cosmic timescale. The interactions can be traced by galaxy distortions and faint streams of stars created by gravitational tides. But a clear view of the galaxy group is difficult to come by, as the deep image also reveals extensive clouds of foreground dust sweeping across the field. The dim, dusty nebulae reflect starlight from our own Milky Way Galaxy and lie only a few hundred light-years above the galactic plane.


User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

On the edge of the known double cone Universe

Post by neufer » Thu Jan 21, 2010 12:48 pm

Today's APOD is a reminder of why yesterday's APOD displayed the Known Universe
as a double cone: what lies in back of the Milky Way "donut" is by & large a mystery.
Art Neuendorffer

User avatar
Ann
4725 Å
Posts: 13308
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Dust and the NGC 7771 Group (2010 Jan 21)

Post by Ann » Fri Oct 07, 2011 8:42 am

My, what a pretty picture! And it has received only one comment apart from the one I'm posting now. I can't understand that. Just look at that fantastically long and convoluted dusty tidal tail emerging from NGC 7771! It's so long and flamboyant that you'd almost think it needs an accelerating universe to even house its cosmic longhand. I wonder what awesome message it's writing for us on the retreating skies? I guess it's not anybody's horoscope, but a message about galaxies emerging out of the elements and structures created by the Big Bang, and then about gravity tossing rocks in the pond, messing up the galaxies' tails.

In any case, that's a great picture, Ken Crawford!

Ann
Color Commentator