All Questions
Tagged with star main-sequence
26
questions
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
12
votes
1
answer
434
views
Is there a relation between mass, radius, and luminosity in deuterium-burning brown dwarfs?
I'm a worldbuilder and my setting has a lot of brown dwarfs.
While I'm trying to keep my setting as science-compliant as possible, I can't seem to find any resources for brown dwarfs like there are ...
- 163
11
votes
1
answer
550
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
9
votes
1
answer
1k
views
Increase in Luminosity of the star
The Luminosity of a star is proportional to the 4 th power of its temperature and square of its radius. Also the mass-luminosity relationship says that the luminosity of star is proportional to ...
- 157
9
votes
1
answer
344
views
What does the surface of a star with a radiative envelope look like?
This image from Wikipedia shows that main sequence stars above 1.5 solar masses have a convective core and a radiative envelope. The surface of our sun grainy because of convection cells right below ...
- 1,758
8
votes
1
answer
552
views
Why does the convective core in an intermediate- to high-mass star shrink?
The image below shows the evolution of the hydrogen mass fraction profile for a 5 solar mass star in the main sequence. I would expect that the size of the convective core stays roughly constant as ...
- 199
7
votes
3
answers
1k
views
When a star enters a red giant phase, does the pressure in its core increase or decrease?
When a star becomes a red giant, does the pressure in its core increase or decrease?
From one side, the only source of pressure in a star is gravity. A red giant is much larger than an ordinary star, ...
- 800
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
5
votes
3
answers
995
views
Is it possible for a star cluster to be composed of main sequence stars?
From what I hear about globular clusters, they are primarily composed of very hot giant stars, which are not the most conducive for life as we know it.
Main sequence stars like our own, due to their ...
- 469
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
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
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
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
4
votes
1
answer
117
views
Catalogs for type K stars and their planetary systems?
I am doing data collection on all type K stars, and their planetary system so I may develop an algorithm for a planetary formation simulation with the Unity game engine.
Where could such a catalog of ...
- 203
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