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11 votes
Accepted

Are the orbits of all triple star systems at least technically unstable?

(Ignoring that all orbits are technically unstable due to the emission of gravitational waves.) There are known solutions to the gravitational three body problem that can be shown to be stable. ...
TimRias's user avatar
  • 2,720
11 votes

Are multiple stars actually more common than singles?

Too long for a comment: There is one ambiguity you are going to have to deal with, because nobody agrees what “star” means. Suppose that you see three points of light in the sky, and then with a ...
Martin Kochanski's user avatar
8 votes

Are multiple stars actually more common than singles?

That's a good question with a non-intuitive answer. The main point is: one has to distinguish stellar systems from stars themselves. Consider an essemble of 30 stellar systems. 33% or 10 of them are ...
planetmaker's user avatar
  • 19.9k
5 votes
Accepted

Could the unseen companion of HR 6819 be a close binary system?

The absolute minimum mass of the unseen companion is $4.2 M_{\odot}$ (and my reading is that this really is an unlikely minimum, requiring an abnormally faint primary for its spectral type and an ...
ProfRob's user avatar
  • 155k
4 votes
Accepted

Calculate the absolute magnitude for a multi-star system

Yes, you are correct. The luminosities can be added. Luminosity is the amount of electromagnetic energy emitted per unit of time (measured in $ \textrm{J} \cdot \textrm{s}^{-1} $ or $\textrm{W}$). So ...
Dieudonné's user avatar
  • 3,361
3 votes
Accepted

Which star system has the highest multiplicity (# of stars), whose orbits are known for all stars?

As of writing this, 11 October 2023, I am reasonably certain that the star systems with the highest multiplicity, whose orbital periods of each of the stars are known, are those of the two septuple ...
Curious Layman's user avatar
2 votes
Accepted

Origin as binaries and multiple system

Many hot stars are born in multiple star systems because the cores of these stars tend to split (see Jeans instability). With lower mass stars this still can happen. However, there are other ways. For ...
WarpPrime's user avatar
  • 6,683
2 votes

Are multiple stars actually more common than singles?

You might also like to consider the probability that a number of the singleton stars that are visible might have once been part of a binary system and have devoured their companion. There may also be ...
Michael Mcgarry's user avatar
1 vote

Is it correct to say that only binary and solitary star systems are stable?

It is quite possible that binary stars average less stable than single stars, that trinary stars average less stable than binary stars, that quarternary stars average less stable than trinary stars, ...
M. A. Golding's user avatar
1 vote

Is it correct to say that only binary and solitary star systems are stable?

No. It isn't proven that any real orbital systems are stable on sufficiently long time scales. Even our (single star) Solar System is not stable. In their paper: On the Dynamical Stability of the ...
Connor Garcia's user avatar
  • 16.3k
1 vote

Is a double quasi-binary system valid?

As far as I know, all known old multiple star systems with stable orbits have highly hierarchical structures. Binary star pairs in those systems orbit much closer to each other than they do to other ...
M. A. Golding's user avatar
1 vote

Is there any planet or black hole where we could experience time dilation like in the movie Interstellar?

You can definitely scratch out any planets, as their gravitational field will not be strong enough. Even a very dense neutron star wouldn’t give much effect, as far as I know. As for black holes, well,...
Pierre Paquette's user avatar
1 vote

Naming convention for multiple star systems

I suppose that the International Astronomical Union has rules for naming stars in multiple systems. I believe the usual rule is to describe the brighter star as A and the dimmer star as B, which works ...
M. A. Golding's user avatar
1 vote

Naming convention for multiple star systems

The purpose of the notation is to indicate how the system is physically constructed, to indicate which stars orbit which - especially useful in hirachically organized stellar systems. So both ways are ...
planetmaker's user avatar
  • 19.9k
1 vote

Which star system has the highest multiplicity (# of stars), whose orbits are known for all stars?

As far as I know, the system with the most stellar members is the black hole at the center of the Milky Way with 8 stars in close orbit. Of course, David Hammen is correct, and if there are other ...
WhatRoughBeast's user avatar

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