Thursday, October 25, 2007

view from the disk

a few days ago, the astronomy picture of the day featured an image taken by photographer, Larry Landolfi, near the mcdonald observatory in west texas. i've never seen the milky way look this crisp with my eyes with the foreground so illuminated... he uses a neat "composite" trick where he takes several images and puts them on top of each other to get a really neat effect. he has some other amazing photographs that you should really check out!


last month i introduced the following picture of our milky way and described some of the features of our flat galaxy. this might be a confusing image of what our galaxy looks likes, but remember that we're inside the big disk looking out thru it.


now, imagine if we could jump in a space craft and fly away from our galaxy, but still sit in line with the disk. we take our trusty hubble space telescope (of course!) and fly 50 million light years away... then turn around to take an image of the milky way.... our view might look like this picture of the "edge on" galaxy, NGC 4013... you can still see the star light shining around the central line of dark dust clouds that block some of the light produced by the stars.


if we fly even farther away, in order to get the whole of the galaxy in the view of our telescope, we might see something like the "needle galaxy" (NGC 4565) that even shows a concentration of bright light at the very center. its difficult to tell exactly what the very center of our galaxy looks like since we're sitting inside it (did you ever see that movie inner space?). maybe the needle galaxy has a lot of stars at its center, or lacks the dust there that would block the starlight from escaping, or maybe there's a massive black hole in the center energizing the surrounding gas to the point of glowing!


now we're out in space and we decide to sit back and look around. we spot this crazy disk galaxy... we call it the pizza dough galaxy, but learn that astronomers on earth all call it ESO 510-G13.


it looks like it could consist of a flat disk of stars and dust like our milky way, but there's a big warp in it. it almost looks like pizza dough as it spins through the air above some brave person's head! thin disks are actually rare and very fragile. a small gravitational bump could cause a disk to distort just like this! they're hard to find in the universe since galaxies are so far away... we're lucky to have such good telescopes to find such cool looking galaxies!

think about what it would look like across our sky if the milky way's disk had a big warp in it like the pizza dough galaxy!

1 comment:

Jimmy said...

It 3:49am and I'm looking for the origin of mankind or at least our final destination. If the poles shift in 2012...well fuck, at least we got to see some of this beautiful and mysterious place.

Jimmy.