by Ann » Sat Aug 04, 2012 5:12 am
Boomer12k wrote:
At 45 times the mass of the Sun...why has it not collapsed into a black hole, or blown up? Is it because of age? Still being young, and hot?
45 times the mass of the Sun is not an impossible "weight" for a star to carry
for a short time. Say, for perhaps five million years or so.
I think that the most massive stars definitely identified contain about 120 times the mass of the Sun. Admittedly I haven't checked it up.
The fact that the star inside the Bubble Nebula is, indeed, blowing a bubble suggests that it is perhaps entering its Wolf-Rayet phase, when the O star starts blowing a ferocious wind. The picture on the left shows another extremely windy O star, HD 148937. The nebulosity seen on two sides of the star is classified as NGC 6164
and NGC 6165. The nebulae have been created by the star, whose hard wind blows gas away from itself. Then the onslaught of ultraviolet photons from the star ionizes the gas that it has blown away from itself. (But another important source of the ionization in this case is that the gas which is blown away by the star slams into the "gas background" further out, the so-called interstellar medium, and this collision between "bodies of gas" produces ionization.)
I think today's APOD looks brilliant, and I really like the mixture of narrowband and RGB imagery.
Boomer12k, your Bubble Nebula images aren't bad, either!
Ann
[quote]Boomer12k wrote:
At 45 times the mass of the Sun...why has it not collapsed into a black hole, or blown up? Is it because of age? Still being young, and hot?[/quote]
45 times the mass of the Sun is not an impossible "weight" for a star to carry [i]for a short time[/i]. Say, for perhaps five million years or so.
I think that the most massive stars definitely identified contain about 120 times the mass of the Sun. Admittedly I haven't checked it up.
[float=left][img]http://www.martinpughastrophotography.id.au/images/NGC6164_6165_Crop_small.jpg[/img][c][size=80]NGC 6164/6165/HD 148937.
Source:http://www.martinpughastrophotography.id.au/
Nebulae/Nebulae_Index.htm[/size][/c][/float]The fact that the star inside the Bubble Nebula is, indeed, blowing a bubble suggests that it is perhaps entering its Wolf-Rayet phase, when the O star starts blowing a ferocious wind. The picture on the left shows another extremely windy O star, HD 148937. The nebulosity seen on two sides of the star is classified as NGC 6164 [i]and[/i] NGC 6165. The nebulae have been created by the star, whose hard wind blows gas away from itself. Then the onslaught of ultraviolet photons from the star ionizes the gas that it has blown away from itself. (But another important source of the ionization in this case is that the gas which is blown away by the star slams into the "gas background" further out, the so-called interstellar medium, and this collision between "bodies of gas" produces ionization.)
I think today's APOD looks brilliant, and I really like the mixture of narrowband and RGB imagery.
Boomer12k, your Bubble Nebula images aren't bad, either! :D
Ann