APOD: Edge on Spiral Galaxy NGC 891 (2010 Feb 25)

[APOD Robot]

Edge on Spiral Galaxy NGC 891

Explanation: This beautiful cosmic portrait features NGC 891. The spiral galaxy spans about 100 thousand light-years and is seen almost exactly edge-on from our perspective. In fact, about 30 million light-years distant in the constellation Andromeda, NGC 891 looks a lot like our Milky Way. At first glance, it has a flat, thin, galactic disk and a central bulge cut along the middle by regions of dark obscuring dust. Also apparent in NGC 891's edge-on presentation are filaments of dust that extend hundreds of light-years above and below the center line. The dust has likely been blown out of the disk by supernova explosions or intense star formation activity. Faint neighboring galaxies can also been seen near this galaxy's disk.

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[neufer]

A close up infrared Hubble Space Telescope image of NGC 891.

Credit: HST/NASA/ESA.

http://antwrp.gsfc.nasa.gov/apod/ap990322.html

[orin stepanek]

Looks a lot like NGC 4565 http://apod.nasa.gov/apod/ap090428.html

[neufer]

Looks a lot like NGC 4565 http://apod.nasa.gov/apod/ap090428.html

"We Have Met The Enemy and He Is Us:"

Code: Select all

NGC                      891              4565
--------------------------------------------------------------
Constellation 	      Andromeda       Coma Berenices
Discoverer           Herschel (1785)   Herschel (1784)
Type 	                SA(s)b?           SA(s)b?
App. dimensions 	  13′.5 × 2′.5      15′.90 × 1′.85
App. magnitude          10.8               10.42
Distance 	           ~30 Mly            ~30 Mly
Redshift  	          528 km/s          1230 km/s

[joecoffee]

Let me begin by saying how much I enjoy the wonderful and inspiring photos shown on APOD by the many talented amateur and professionals who submit them. It really breaks up a boring day to view these images.

The image of NGC 891, posted today, Feb. 25, 2010 looks to be slightly wavy, note right side how it dips as compared to the left side. I was wondering if perhaps this is indicative of all or most spirals or if perhaps, as I have seen in photos of galaxies in collision, showing that some gravitational influence has caused this effect––or am I just imagining the wave.

[neufer]

The image of NGC 891, posted today, Feb. 25, 2010 looks to be slightly wavy, note right side how it dips as compared to the left side. I was wondering if perhaps this is indicative of all or most spirals or if perhaps, as I have seen in photos of galaxies in collision, showing that some gravitational influence has caused this effect––or am I just imagining the wave.

The waviness is real and is common to most spirals including our own.
Such waviness is no doubt the result of the gravitational influence of nearby galaxies (e.g., the Magellanic clouds).

[joecoffee]

Ah ha. That makes sense. Thank you.

[jetpiston]

I wonder if anyone here has seen John Carpenter and Dan O'Bannon's film Dark Star in which the subject of this APOD is immortalized in the song, When Twilight Falls on NGC 891.

[RJN]

Dark Star is one of my favorite movies! It is really funny. No one on the spaceship wants to feed the alien (and for good reason). People on Earth have really lost interest in Dark Star's mission, making communications with Earth awkward and pretty funny. One of the bombs on board decides it wants to explode, so the astronauts try to talk the bomb out of it.

I had no idea that song was in the movie. Although Jerry wrote this APOD, if I had known I would have told him of the connection, as this is just the type of movie he would like as well. If anyone else out there likes both comedy and science fiction, this would be a good movie to rent. The book is just as funny.

[orin stepanek]

http://www.youtube.com/watch?v=qjGRySVyTDk