Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: hihello on 25/10/2009 08:16:42

Title: Are the spiral arms of a spiral galaxy visible?
Post by: hihello on 25/10/2009 08:16:42

hi i was just wondering,

 When can you see the spiral arms of a spiral galaxy?

i always thought that you can see it form any direction but i also heard that you can see it when some or all of its face is pointed towards us
 or when its edge is pointed towards us but im not too sure...


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Title: Re: Are the spiral arms of a spiral galaxy visible?
Post by: LeeE on 25/10/2009 12:38:07

When I tried the google link it didn't show any edge-on spirals, so here's one of NGC891, courtesy of nasa:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fapod.nasa.gov%2Fapod%2Fimage%2F9702%2Fngc891_kp.jpg&hash=bf8d10152b3759e45a4a25eb525e266d)

As you can see, you can't see any spiral arms.  Actually, this one has been hypothesised to have a central bar, rather than the more 'normal' spiral arms.  It does nicely show up the dust though.

Title: Re: Are the spiral arms of a spiral galaxy visible?
Post by: GlentoranMark on 31/10/2009 15:18:27

Why not try some real science and see if you can spot a spiral galaxy?

http://www.galaxyzoo.org/

Title: Re: Are the spiral arms of a spiral galaxy visible?
Post by: LeeE on 31/10/2009 21:20:55

Lol - I did Galaxy Zoo for a while, until I realised what a huge time-drain it had become.

Title: Are the spiral arms of a spiral galaxy visible?
Post by: GlentoranMark on 01/11/2009 01:57:34

Its an addictive site but a worthwhile cause  [:)]