NGC 7331 Wheels within wheels (APOD 12 Jul 2008)

astrolabe · Post by **astrolabe** » Sat Jul 12, 2008 5:17 am

Hello All,

http://antwrp.gsfc.nasa.gov/apod/ap080308.html

What a beautiful sight! It looks as if the bluish outer area is tilted up on the right and down on the left with respect to the brighter inner half of the disk which appears more horizontal.

henk21cm · Post by **henk21cm** » Sat Jul 12, 2008 9:28 am

astrolabe wrote:It looks as if the bluish outer area is tilted up on the right and down on the left with respect to the brighter inner half of the disk which appears more horizontal.

Indeed, agreed. The center looks like a huge ball, which sagged through the ice and is now partially floating on water.

I notice another sort of asymmetry in 7331. Around the center there is a glow. What i call Above is where the Deer Lick group is visible, below is where the bright blue 'spiked' star is visible. The glow below is broader than the glow above. This might be an optical illusion, so i cut out 7331 (without the Deer Lick group) and rotated 7331 over 4 possible angles. Independently of the orientation of the rotated image, the glow (originally) below looks to me broader than the glow above.

Yet it may still be an illusion. Above, the spiral arms add an overwhelming light intensity, outradiating the central glow.

orin stepanek · Post by **orin stepanek** » Sat Jul 12, 2008 12:37 pm

astrolabe wrote:Hello All,

http://antwrp.gsfc.nasa.gov/apod/ap080308.html

What a beautiful sight! It looks as if the bluish outer area is tilted up on the right and down on the left with respect to the brighter inner half of the disk which appears more horizontal.

Is this the link you wanted?

http://apod.nasa.gov/apod/ap080712.html

Orin

astrolabe · Post by **astrolabe** » Sat Jul 12, 2008 2:15 pm

Hello orin stepanuck,

Thank you, of course it is.

(To bad they didn't make the emoticon bigger.) The only flaw in computer technology is that does what one is telling it to, not what one is thinking.

orin stepanek · Post by **orin stepanek** » Sat Jul 12, 2008 3:48 pm

Hi Astrolabe. Think nothing of it. I know the feeling.

It looks like the center of the galaxy is leaning a bit from the rim of the galaxy. I wonder if something we cannot see is disturbing the outer plane a bit.

Maybe a merger with a dwarf galaxy from behind?

Orin

bystander · Post by **bystander** » Mon Jul 14, 2008 12:43 pm

I also noticed the warpage of the disk and the asymmetry of the central bulge in NGC 7331. The central bulge is also asymmetrical about its axis and there seems to be alot of new stars in the outer disk (lot of blue). I agree with Orin that there must be some interaction with another galaxy, possibly a dwarf companion.

At 6 o'clock to the center of the galaxy is a smudge. Might this be a dwarf companion?

astrolabe · Post by **astrolabe** » Tue Jul 15, 2008 1:45 am

Hello bystander,

I see what you mean. It appears to have a slight hint of a spiral shape but it's hard to tell if it's at a distance or in NGC 7331's area of influence. Something I do believe has tugged at it's shape. If your object is in fact that close, and in it's current attitude, then maybe it has an eccentric orbit like Uranus in our System so could account for the planar descrepancies in the outer arms. Good eyes, kid.

Starship Asterisk*

NGC 7331 Wheels within wheels (APOD 12 Jul 2008)

NGC 7331 Wheels within wheels (APOD 12 Jul 2008)

Re: NGC 7331 Wheels within wheels

Re: NGC 7331 Wheels within wheels