All Questions
Tagged with star main-sequence
26
questions
4
votes
2
answers
234
views
Does the density in the core of a "higher mass" star stay generally constant while it evolves on the MS?
We know the CNO cycle produces the majority of energy production in a "higher mass star" of approx. over 2 solar masses and the core is convective due to the large temperature gradient. My professor ...
- 1,111
6
votes
1
answer
585
views
On a Hertzsprung-Russell diagram, why is the main-sequence line squiggly?
When I look at a Hertzsprung-Russell diagram, I'm able to see a main-sequence line from the most luminous main-sequence stars at the top left to the dimmest main-sequence stars at the bottom right. ...
- 263
3
votes
1
answer
3k
views
How long does it take a star to transition from main sequence to red giant?
I have read that it takes billions of years for stars of approximately the size of the Sun to get through the main sequence, after which it will enter the red giant phase. When that happens, how long ...
- 133
11
votes
1
answer
551
views
How does a star's rotation affect a star on the main sequence?
I searched and have found that the questions mainly focus on neutron stars, white dwarfs and black holes. This was not what I want.
Basically, the bigger the star's mass is, the more intense its ...
- 263
15
votes
2
answers
5k
views
Does a star fuse helium to beryllium on the main sequence?
When a star has finished fusing all its hydrogen into helium, it will then start fusing helium into beryllium and so on and so forth up until iron.
When the star is fusing to beryllium, will the ...
- 1,311
1
vote
0
answers
63
views
Are there simplified M-L, M-R, and lifetime equations for non main sequence stars?
To give some context - I am trying to create a simple program that outputs the stellar properties of a star when given its initial mass and current age.
e.g.
Input
Initial Mass = 2e30kg
Age = 4.6 ...
- 11
4
votes
4
answers
4k
views
Why is the main sequence often called 'zero age' main sequence?
The main sequence stage for a star begins after it stars burning hydrogen into helium. This is often referred to as the zero age main sequence.
This is confusing since stars have already lived ...
- 822
4
votes
2
answers
659
views
Why do post main sequence stars enter the red giants branch?
I am an early graduate student in astronomy and have hard time understanding why do post-MS stars move up the RGB.
Here is what I understand about post main sequence evolution of stars. As their ...
- 41
4
votes
1
answer
2k
views
What is the largest hydrogen-burning star?
I am wondering what is the largest known core hydrogen-burning star? A look at the list of largest known stars on Wikipedia seems to indicate VV Cephei B (at the bottom of the list), but I would like ...
- 2,673
4
votes
1
answer
292
views
What's an order-of-magnitude main sequence star look like?
I'm looking for a very rough, order-of-magnitude approach to the main sequence.
What I mean is, I have a spherically-symmetric hydrogen distribution. I'm looking to get a rough approximation for ...
- 173
3
votes
2
answers
600
views
How can pre-main sequence stars radiate more energy than main-sequence stars?
How can a pre-main sequence star radiate more energy by gravitational contraction than a main-sequence star can by hydrogen fusion?
- 133