Whats going on here?
Posted: Sat Feb 06, 2010 9:52 pm
Hi Folks
Whats going on here. And why is there a little version upper right .?
![Image](http://www.universetoday.com/wp-content/uploads/2009/12/Where-in-the-Universe.jpg)
Mark
Whats going on here. And why is there a little version upper right .?
![Image](http://www.universetoday.com/wp-content/uploads/2009/12/Where-in-the-Universe.jpg)
Mark
APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
geckzilla wrote:You know the ring structure surrounding the central "star" is formed by innumerable stars so why stop there and decide that the central one is one big star and not similarly composed of billions of stars?
It isn't. It clearly falls away in intensity as you go outwards, as would be expected for a gravitationally bound collection of stars. A huge star would have hard edges. Of course, a star of that size can't physically exist, because it couldn't generate enough energy to support itself against the force of gravity. If an object of that size sprang into existence, it would collapse into a supermassive black hole.wonderboy wrote:What if it IS a big star?
The image distorts the actual brightness profiles. From inside either galaxy, all those other stars are still very far away. You'd feel heat from them in the same way you feel heat on your face when you stand outside under the Milky Way.wonderboy wrote:it looks like there are two versions of this galaxy (obviously not the same galaxy, but similar) one is top right of the centre collection of stars and one is immediately right behind the spiral arms. I say spiral arms because to me, if you look closely, there appears to be two arms, both incredulously long, which wrap itself around the centre of the galaxy.
surely the heat from that collection of stars must be felt all the way through that galaxy?
No. He was telling you , even though these stars look like they are all clumped together in one huge mass, They are not. there are still huge distances between them.wonderboy wrote:Now I don't know if your being funny or not there, but I have never felt heat on my face. was that sarcasm?
this one is truly large. but consider a smaller one which is still big enough that would collapse in long term due to gravity, then is it possible that we observe it just like a star before it completely collapses to form a black hole?Chris Peterson wrote:...If an object of that size sprang into existence, it would collapse into a super massive black hole.
Not really- just trying to give a sense of scale. Like knowing that the energy received from the radios on our deep space probes is similar to the energy you feel on your face in Los Angeles from a match being lit in New York.wonderboy wrote:Now I don't know if your being funny or not there, but I have never felt heat on my face :(. was that sarcasm?
Stars simply can't get very big- the largest mass possible is only a couple hundred times that of the Sun, and the largest diameter possible is a few astronomical units. That sounds impressive compared with our own sun, but is still only visible as a point source from Earth (with a few notable, nearby exceptions).Amir wrote:this one is truly large. but consider a smaller one which is still big enough that would collapse in long term due to gravity, then is it possible that we observe it just like a star before it completely collapses to form a black hole?
i mean i know it's too big to remain a star but for that short time before it collapses does it look like a star as it generate energy?