Astronomy never stops to amaze me...

[emadmoussa]

Galaxies and nebuale aside, just thinking of the size of certain stars makes made shudder. Nothing new, but can't help visualizing this picture below every time my eyes fall on Betelgeuse, Aldebaran or Antares..

Anyway, hold your breath till Betelgeuse turns supernova!!

[ScottS]

Mind boggling isn't it. I'm just glad there's plenty of distance between us and Betelgeuse. There's even bigger ones out there!

[Space Dragon]

Isn't the diameter of Betelgeuse about the same as the distance we are from the Sun.......I think that was one of the first astro facts I heard as a child but it still amazes me.

[emadmoussa]

Isn't the diameter of Betelgeuse about the same as the distance we are from the Sun.......I think that was one of the first astro facts I heard as a child but it still amazes me.

It's about 1.5 astronomical units. From the the sun the asteroid belt proximately.

[ScottS]

Now read about NML Cygni

[Beulah]

Thanks for that Emad. That's the best scale comparison I've seen so far.  

[emadmoussa]

Now read about NML Cygni

Yep this one is ''astronomically'' huge. I think it's about 1500 times bigger than the sun...Anyway, will keep my eyes open for another hypernova! Add to that VY Canis Majoris and you'll get absolutely stunned.

[Tinker1947]

While we understand that distances and the size of other Stars compared to ours is huge it still takes a lot to get your head round it, when i read about the largest Galaxy found and the size that just to big to take in......

[emadmoussa]

While we understand that distances and the size of other Stars compared to ours is huge it still takes a lot to get your head round it, when i read about the largest Galaxy found and the size that just to big to take in......

Indeed - just imaging those massive differences in sizes between stars and then apply that to galaxies...just thinking that our Milky Way is only a spec in comparison to NGC 6872 makes my head wobble....I have to stop here. It's going into a confusing loop same as the time line...

[ronin]

It's about 1.5 astronomical units. From the the sun the asteroid belt proximately.

Mars is 1.5 to 1.6 AU.

If the asteroids were at 1.5 AU then Mars would not be a planet - it would have failed the criteria to have cleared it's orbit.

Suspect you mean another 1.5AU from us making the asteroid belt about 2.5AU in radius.

Generally given as 2-4AU radius.

[emadmoussa]

Mars is 1.5 to 1.6 AU.

If the asteroids were at 1.5 AU then Mars would not be a planet - it would have failed the criteria to have cleared it's orbit.

Suspect you mean another 1.5AU from us making the asteroid belt about 2.5AU in radius.

Generally given as 2-4AU radius.

Correct.

[emadmoussa]

It's about 1.5 astronomical units. From the the sun the asteroid belt proximately.

#Correction:   distance to asteroid belt is 2.5 AU (149.000.000 x 2.4) - thanks Ronin for pointing out mistake.

[Tinker1947]

This Galaxy is up there to view, will need a lot of aperture or a DSLR with some longish subs.......

http://en.wikipedia.org/wiki/NGC_262

[Tinker1947]

Another biggy......

http://en.wikipedia.org/wiki/IC_1101

[emadmoussa]

Another biggy......

http://en.wikipedia.org/wiki/IC_1101

Wonderful. I recently read about this one...it is jaw dropping how big it is... It's eating galaxies and growing, kind of cosmological carnivore. 

[Knight of Clear Skies]

These giant stars are vast indeed, but they are also amazingly diffuse. The density of the outer envelope is less than a tenth of that of Earth's atmosphere.

[forasibi]

What a great visual aid!

[Lancashire Astroguy]

These giant stars are vast indeed, but they are also amazingly diffuse. The density of the outer envelope is less than a tenth of that of Earth's atmosphere.

I often think of red supergiants being more like seething red hot nebulae than stars. Certainly if you saw one up close (or at least from a safe distance!) it wouldn't look at all sun-like. They don't have a well-defined photosphere, and are probably not even vaguely spherical as the outer layers swell in and out of hydrostatic equilibrium.

[starman1969]

Thanks for your post. Those images are a very good example the scale of stars. Often when I'm out on a clear night I'll look at Betelgeuse and try to imagine it going supernova. Of course that could be anytime now or in the next couple of million years or so, but it will happen.

[astro mick]

Its mind boggling stuff,and the Universe is full of wonders.

But there is one thing that really bugs me,and that is when Professional. Astronomers refer to the Sun as boring and average.

Our Star is far from this,because as far as we know at the moment its the only Star that enables us to be here.It has all the special qualities that a lot of Stars don't have.

The Sun is everything to life on earth,and without it we would,nt be here at all.

Lets see our Star as something very special,because indeed it is.

Mick.

P.S. Its not my intention to hi-jack this thread,so please don't treat it is as so.

[faulksy]

Thanks for your post. Those images are a very good example the scale of stars. Often when I'm out on a clear night I'll look at Betelgeuse and try to imagine it going supernova. Of course that could be anytime now or in the next couple of million years or so, but it will happen.

it could of already happened, who nos we might see it tonight