Starship Asterisk*

by **Chris Peterson** » Sun Mar 28, 2010 2:25 pm

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?

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).

A star supports itself against gravity while it sustains fusion, and very rapidly collapses once it uses up its fuel. If the star is more than a few solar masses, it will produce a supernova and end up as a black hole. Such a thing would be observable.

by **Chris Peterson** » Sun Mar 28, 2010 2:14 pm

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?

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.

The Milky Way genuinely produces heat, and with sensitive instruments you could measure that heat. But it isn't on a human scale, and even if you were in the galactic core, it still wouldn't be.

by **wonderboy** » Sun Mar 28, 2010 2:01 pm

I would love to see that, i think cameras should be kept rolling on eta carinae, that might be one of the coolest things ive ever seen if im honest. What is the deal with that star anyway? is it or isnt it?

by **Amir** » Sun Mar 28, 2010 1:47 pm

Chris Peterson wrote:...If an object of that size sprang into existence, it would collapse into a super massive black hole.

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?

by **wonderboy** » Sun Mar 28, 2010 12:11 pm

I seeeeeeeeee Im just bein stupid, I live in glasgow and drove from there to the bottom of wales and back, all in all I did 800 miles and drove it non stop. all for a puppy. Im knackered so I apologise that my brain isnt working.

I forget I'm looking at a galaxy of course the stars are distanced from each other. I shoulda known that.

by **The Code** » Sun Mar 28, 2010 11:56 am

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?

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.

Mark

by **wonderboy** » Sun Mar 28, 2010 9:44 am

Now I don't know if your being funny or not there, but I have never felt heat on my face

. was that sarcasm?

by **Chris Peterson** » Thu Mar 25, 2010 2:13 pm

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?

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.

by **wonderboy** » Thu Mar 25, 2010 10:42 am

Fair play. I'm still learning you see, so thanks for informing me. 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?

by **Chris Peterson** » Fri Mar 19, 2010 4:45 pm

wonderboy wrote:What if it IS a big star?

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.

by **wonderboy** » Fri Mar 19, 2010 4:24 pm

What if it IS a big star?

by **The Code** » Sat Feb 06, 2010 11:02 pm

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?

Because the only thing I could say after what you just said is OH MY GOD

That,s because i do understand what you said.

Mind blowing. Thanks

by **geckzilla** » Sat Feb 06, 2010 10:53 pm

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?

by **The Code** » Sat Feb 06, 2010 10:45 pm

That has got to be a big star, unless its in the foreground ? Great Photo.

by **geckzilla** » Sat Feb 06, 2010 10:29 pm

The reason the mini one is there is because, as Einstein said, "God is subtle . . . "

by **bystander** » Sat Feb 06, 2010 10:04 pm

APOD: 2004 August 15 - Hoag's Object: A Strange Ring Galaxy

by **The Code** » Sat Feb 06, 2010 9:52 pm

Hi Folks

Whats going on here. And why is there a little version upper right .?

Mark

Starship Asterisk*

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