Astronomy Stack Exchange
Astronomy Stack Exchange

Questions tagged [binary-star]

Questions regarding a pair of stars that are gravitationally bound and orbit around their barycenter.

Binary stars are double stars, though some double stars are actually far apart, but merely seem to be close together.

203 questions
30
votes
1 answer

How far apart are stars in a binary system?

I'm wondering how far apart from one another the stars are in binary systems. What is the distribution of the separation between binary stars? Are most of the binary stars very far apart like Sirius (8.2 to 31.5 AU)? Are there many stars in orbits…
usernumber
  • 17,492
  • 3
  • 54
  • 133
9
votes
2 answers

How many actual stars are Polaris?

I am getting conflicting accounts everywhere. I heard astronomers saying Polaris is a 3-star system. Some say they are binary but are optical-doubled with a 3rd. Phil Plait a renowned astronomer wrote in his book Bad Astronomy that Polaris is…
fahadash
  • 501
  • 3
  • 11
6
votes
1 answer

What percentage of visual stars are actually binary stars?

I know this is such a thing as a binary star where for example two stars rotate around a central point of gravity but to the naked eye are just a star. What I do not know is how common this is (approximately)?
esé
  • 327
  • 2
  • 7
5
votes
0 answers

HR 6819 "Vampire" star - mass disparity in binary star system

Regarding the two B-type stars of the HR 6819 system, a recent news item (2 March 2022), European Southern Observatory researchers find 'vampire' star sucking outer layers of companion star states, The current mass of the "vampire" star is roughly…
Fred
  • 2,169
  • 1
  • 10
  • 27
5
votes
1 answer

Which binary star system has a greatest angular distance?

Visible from the Earth, which binary star system has greatest angular distance ?
user3715778
  • 257
  • 1
  • 4
5
votes
1 answer

Do main sequence stars in binaries transfer mass by Roche lobe overflow?

It is known that binary star components containing red giant can under go mass transfer when their radii exceeds the Roche limt. Do main sequence binary stars also undergo mass transfer by this mechanism?
Jiswin
  • 177
  • 5
5
votes
2 answers

Double Planet Orbiting Wide Binary Star?

Right now I'm writing a sci-fi story that develops in a double planet. But that's not all, the double planet (along with a couple more planets) orbit a big star and the whole system is orbited by another star (about 100 AU from the central star.) I…
A.C Louis
  • 153
  • 2
4
votes
3 answers

Is there a logical reason why we see no back and forth aberration effects when observing binary stars?

I read this article, Questioning Einstein: Is Relativity Necessary? (Bethell (2010), Proc. Natural Philosophy Alliance, v.6, no. 2), regarding the 2 stars of Mizar A and wondering if it is true that we do not see back and forth aberration effects…
Dubious
  • 49
  • 1
4
votes
1 answer

Does binarity play a role in spectral fitting?

Most of the spectroscopic surveys like SDSS classify stars into one pure spectral type. However, a large fraction of stars are in binaries. Can we know whether a spectral fitting is good enough? Is there something like $\chi^2$? In other words, is…
questionhang
  • 3,137
  • 1
  • 20
  • 31
3
votes
1 answer

Binary star not exceeding Roche Lobe?

Is it possible that a binary star doesn't exceed its Roche lobe and so when the second star becomes a red giant, instead of accreting some of its plasma onto the white dwarf that it becomes a white dwarf itself which causes there to be no supernova?
Caters
  • 269
  • 2
  • 7
3
votes
2 answers

Filling the Roche Lobe

For mass transfer in a binary system, one star must fill its Roche lobe. What determines whether a star in a binary system will fill its Roche Lobe? How will I calculate it? I can't find any mathematical formula that shows any equation of mass…
Arnab Chowdhury
  • 427
  • 2
  • 6
2
votes
2 answers

can we see all binary stars as pairs?

As it is obvious from the question title is there any restriction or cases that we can see the binary stars as not in pairs also is there any binary stars doesn't linked together by gravity ? I know the definition of binary stars that it is a…
Mohamed IBrahim
  • 65
  • 4
2
votes
1 answer

Semi-major axis in a binary star system

The semi-major axis a here, what exactly does it represent? Point it out in the image below.
d1ep
  • 21
  • 1
  • 3
2
votes
1 answer

Could the word "multiple stars" include binary stars?

We are translating some illustrated book for kids about astronomy, and then have a question as in the title. Referring to Wikipedia etc., It appears that "binary stars" represents the star systems of two stars, whereas "multiple stars" does those of…
Taiki Bessho
  • 123
  • 4
2
votes
1 answer

Are there currently observed systems of close (narrow) binary brown dwarfs?

All over the Universe, there are (gravitationally bound) binary star systems. Considering the huge number of brown dwarfs, are there currently known double systems of gravitationally bound binary brown dwarfs? Given their comparatively low…
Michael Würthner
  • 125
  • 4
1
2