Starship Asterisk*

Ann, thank you sincerely for pointing out the comparison between Andromeda and M101 (the Whirlpool Galaxy?). What a dramatic contrast! So, what I thought of as evidence of a great deal of new star formation along Andromeda's rim was nothing compared to other galaxies. Very instructive.

Am I correct in assuming that the blue stars out along Andromeda's edges are O stars? If so they are comparitively young stars that don't live very long on the universal time scale. They would all be expected to go supernova within the next 10 million years or so, wouldn't they? I bring this up because I'm wondering if any supernova's have been observered in Andromeda.

Bruce

[quote="BDanielMayfield"]Yes indeed Anthony. This is a truly stunning image. One of the things I find a bit surprising about this is how much new construction is going on out in the 'burbs, of our galactic neighbor. There must be a lot of gas out along the rim of Andromeda to supply all these active star forming regions such as the happy face nebula ya'll are discussing. Do you concur?

Bruce[/quote]

Indeed. Andromeda is a perfect illustration of the kind of galaxy where the outlying suburbs are blue while the very large inner regions are yellow! Very close to the center you get some blue stars again, and the largest concentration of young stars in M31, NGC 206, is not right at the visible edge of the galaxy.

Practically all spiral galaxies have yellow centers and blue "edges" (make that the edges of the visible disk), but Andromeda has a very big yellow center and rather faint blue edges. Compare Andromeda with [url=http://www.ia.ucsb.edu/pa/image.aspx?pkey=2613&Position=1]M101[/url], the Pinwheel Galaxy, which has a small yellow center and a huge blue "disk", mostly made up of large arms.

Ann

Yes indeed Anthony. This is a truly stunning image. One of the things I find a bit surprising about this is how much new construction is going on out in the 'burbs, of our galactic neighbor. There must be a lot of gas out along the rim of Andromeda to supply all these active star forming regions such as the happy face nebula ya'll are discussing. Do you concur?

Bruce

[quote="hstarbuck"]There is a pinkish happy face in the bottom left hand corner. Kind of looks like the Cheshire Cat. :mrgreen: I am just tryin to get 100 posts.[/quote]
Given its red color, I would guess that it's an emission nebula, the glow of hydrogen gas ionized by ultraviolet radiation from a very hot star. It is not labeled on SkySafari 3 Pro, so I don't know if it has been catalogued.

P.S. -- Please invite me to the party when you're promoted to science officer!

P.P.S. -- This is a jaw-droppingly beautiful picture. Wow, seeing individual stars in the Andromeda Galaxy.

Yes, I saw the happy face myself. Now looking at it again, and considering the season, we could call it a jack-o-lantern.

There is a pinkish happy face in the bottom left hand corner. Kind of looks like the Cheshire Cat. :mrgreen: I am just tryin to get 100 posts.

::reading along today's apod...::: 2.5 million Ly distant mhmm ok arms of neighboring galaxy, k gotcha <shocked look falls onto face> wait.... 2,500,000 light years. <faces goes incredulous>.... <sigh> ladies and gentlemen, behold. We live in the future.

I love science.. Especially astronomy... So massive numbers like this are not foreign.. But sometimes it hits me.
This picture is detailed........ So unimaginably well when you think about how... Mind boggelingly huge 2,500,000 light years is. Can you imagine just a few short years ago the breaking news was that extra terrestrial planets had moons and those "nebulae" in the sky were in fact other galaxies?
Imagine Galileos wonder if he could see this.
Imagine what humans will be capable of in a mear 200-300 years, much less 2-3,000.
Our species has so much potential. A lot of that potential is, to me, represented by images like this.
It may not be razor perfect sharp, but wow. This species amazes me. Never stop exploring.
P.s. I apologize for any random words. My phone may have auto corrected and it'd drive me bonkers to scroll through....<face palm>

Bob and Janice Fera are a husband-and-wife team of great astrophotographers. It's so nice to see them getting an APOD! And their picture of NGC 206 and the southwestern part of Andromeda is superb. Please note the "graininess" of the blue populations of Andromeda, as they are made up of relatively few but bright stars. Note, in contrast, the perfect smoothness of the population seen at upper right in today's APOD. The stars here are old, mostly faint, and very numerous.

Ann

[url=http://apod.nasa.gov/apod/ap121024.html][img]http://apod.nasa.gov/apod/calendar/S_121024.jpg[/img] [size=150]NGC 206 and the Star Clouds of Andromeda[/size][/url]

[b] Explanation: [/b] The large stellar association cataloged as [url=http://apod.nasa.gov/apod/ap990402.html]NGC 206[/url] is nestled within the dusty arms of neighboring [url=http://www.seds.org/messier/m/m031.html]spiral galaxy Andromeda[/url] (M31), 2.5 million light-years distant. Seen near the center of [url=http://www.feraphotography.com/AM14/Ngc206.html]this gorgeous close-up[/url] of the southwestern [url=http://apod.nasa.gov/apod/ap061228.html]extent[/url] of Andromeda's disk, the bright, blue [url=http://adsabs.harvard.edu/abs/1996ApJ...468..633H]stars of NGC 206[/url] indicate its youth. Its youngest massive stars are less than 10 million years old. Much larger than the clusters of young stars [url=http://apod.nasa.gov/apod/ap120912.html]in the disk of our Milky Way galaxy known as open or galactic clusters, NGC 206[/url] spans about 4,000 light-years. That's comparable in size to the giant stellar nurseries [url=http://apod.nasa.gov/apod/ap031209.html]NGC 604[/url] in nearby spiral [url=http://apod.nasa.gov/apod/ap101203.html]M33[/url] and the [url=http://apod.nasa.gov/apod/ap090916.html]Tarantula Nebula[/url], in the Large Magellanic Cloud.

[b][table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=121023]<< Previous APOD[/url][/td] [td=center][url=http://asterisk.apod.com/view_retro.php?date=1024]This Day in APOD[/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=121025]Next APOD >>[/url][/td][/tr][/table][/b]