Questions tagged [binary-star]

Question regarding a pair of stars that are gravitationally linked and orbit around their barycenter.

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36 views

Does the orbits of stars in a binary system have a common focus, which is the center of mass of the stars?

I know that when a planet orbits a star (and assume the star is stationary because its mass is >> the mass of the planet), the orbit is an ellipse, and the star sits at one of the foci of the ellipse. ...
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1answer
60 views

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.
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QQ Boo binary star

I need infos about this binary star, QQ Boo, when did it discovered, infos about each star in the binary system and infos about its light curve. I have already search through simbad and aavso websites ...
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1answer
72 views

How many exoplanets have been found around binary stars?

This XKCD whatif talks about circumbinary and [the other kind of] exoplanets. How many such exoplanets have actually been discovered? I tried to look it up at exoplanets.org, but didn't find a column ...
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1answer
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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 (...
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3answers
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Why are there so many binary systems?

Most star systems are binary, but why is that? Why would new stars form close to others, and not (relatively) evenly spread? And even if they are clustered close together, why are the majority binary? ...
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1answer
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Where does Love's number come from in $\delta m = \frac{1}{2}k_2M_2\lbrace\frac{R_1}{r_\star}\rbrace^3$, the formula for the mass of a tidal bulge?

My question refers to page 165 of this paper. Specifically, how does one derive the equation $\delta m = \frac{1}{2}k_2M_2\lbrace\frac{R_1}{r_\star}\rbrace^3$ for the mass of a tidal bulge? A full ...
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1answer
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Why is a giant planet around a tiny star unusual when binary stars are normal?

Inspired by this BBC article and the corresponding journal article about the M dwarf star GJ 3512. The Jupiter-like world is unusually large compared with its host star, contradicting a widely held ...
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Night-Day Cycles in S-Type Planetary Systems

I am a writer and space enthusiast. For a story I am currently writing I would like to have a planet which orbits a star which resembles the sun, which in turn orbits another star. In this situation ...
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Derivation of a formula for the mass of a tidal bulge and tidal torque

I've been looking into the tidal mechanism for a binary star system and seem to have hit a brick wall. In the literature (see below), little explanation is given to justify the equations (9.60), (9.61)...
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1answer
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By convention, when observing an exoplanet, is the observer's line of sight (on Earth) perpendicular to the plane of sky?

This is just a quick question. In this picture of the orbit of an exoplanet, is the observer's line of sight perpendicular to the plane of reference, which is in the +z direction on the diagram? In ...
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Are there any double stars that I can actually see orbit each other?

If I had a nice amateur telescope†, are there any multiple star systems that I could observe over a few years or a few decades and actually see the movement of one or both of them over time? My short ...
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Could an Applegate-like mechanism operate in AM CVn systems?

One of the controversies surrounding the detection of exoplanets around post-common envelope binaries is the possibility that the orbital period variations observed might be the result of the ...
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Roche lobe - flow of mass

In which situation can smaller star in binary fill the Roche lobe? When flow mass of smaller star to larger star? Smaller star fill the Roche lobe in Algol paradox. Does the mass of smaller star ...
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Depth of primary and secondary minimum in a light curve

How can I explain approximately the same depth of primary and secondary minimum in light curve? I observe star HD 36486. I tried filters MOST and BRITE. Is it related with photometric filter? When ...
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2answers
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How does one calculate inclination from a graph of radial velocity?

If a binary star system has a non-zero inclination, how would that show up in a graph of radial velocity? How could I then extract the inclination from the graph?
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How accurate are the new visualisations of V404 Cygni

A number of pictures and some animations similar to the ones below have had much press recently. Clearly the colours are artificial, but I wondered how accurately the represent the geometry of the ...
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1answer
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How to improve efficiency in periodicity detection?

Our data set has $10^4$ data points, but has a long baseline and many gaps. If we bin the data, there would be $10^8$ data points ($[t,\rm {value}]$), but only about 1% are non-zero values. How to ...
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1answer
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Mass of a potential black hole in a binary system

So I've been given the velocity curve, parallax and apparent magnitude of a star in a binary system with what is potentially a black hole. I've calculated from the apparent magnitude and parallax that ...
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2answers
240 views

Binary pairings that haven't been discovered yet?

Question: Are there any kinds of binary pairings that haven't been discovered yet? Any that are particularly significant, or that might shed some light on binary stellar evolution or theories of ...
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1answer
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How to separate binary and optical stellar pairs?

I have list of stellar pairs from The Washington Double Star Catalog (WDS), i.e. I have next parameters: angular separations position angles stellar magnitudes of both components Additionally I have ...
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1answer
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Doing Correct Calculations with Binary Star Systems

I've been experimenting with Binary Star System calculations but came across some issues. I can correctly calculate the Semi-Major Axis of the Earth's orbit around the Sun by doing the equation: ...
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1answer
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What is the reason for magnetic braking?

What is the reason of Magnetic Braking in contact binary stars? Just dark spots? I mean hot spots can have this effect on binaries.
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1answer
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Are there any good images of Sirius B at apastron in the Sirius system?

Sirius B has a distance to Sirius A of 11 arc seconds at apastron; are there any good images of it at that point in its orbit?
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What happens when a star gets hit by a supernova?

This may sound like a strange question, but say that two stars are relatively next to one another in a binary star system, what would happen to one of the stars if the other went supernova? Would it ...
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Total angular momentum in system of binary brown dwarfs on wide orbit from primary star

I want to calculate the total angular momentum of a system in which two brown dwarfs are orbiting one another (P ~ 10 years), and this system is stably orbiting a third primary ZAMS star (P ~ $10^4$ ...
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Sinusoidal Light curve of an eclipsing binary

This light curve seems really weird to me, I'm used to seeing light curves where the barycenter is a straight line. It either stays at a place, moves at a constant speed or slowly increases its speed. ...
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How do isolated binary compact systems survive their formational supernovae?

In a broad sense I'm trying to understand how a binary black hole or neutron star systems can form from isolated binary massive star systems (i.e., other than from migration within rich BH/NS clusters)...
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What are the apparent visual magnitudes of Spica A and Spica B?

What would be the (theoretical) apparent visual magnitudes of Spica A and Spica B (since they are too close together to be resolved telescopically)? The Spica System is 77 parsecs away, and the ...
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2answers
200 views

Can Two Stars of One Same Type Orbit Each Other?

This is a simple, textbook definition of a binary star orbit. One low-mass star orbits a higher-mass star in a narrow but definitive center. For example, the high-mass star would be our own sun--a G-...
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Observing eclipsing binaries

In a matter of weeks, I will be performing my first observation using a 25-cm Newton telescope (+CCD camera) and would be grateful for advice regarding an otherwise basic research that I have decided ...
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2answers
440 views

Is a supernova powerful enough to destroy the other star in a binary system?

(This question was originally posted via World Building, but I was instructed to post it here) https://worldbuilding.stackexchange.com/questions/109457/is-a-supernova-powerful-to-destroy-the-other-...
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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 ...
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2answers
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What is the spectral reflectance of starlight in a close binary?

In a close-orbiting binary pair, a small but significant fraction of the light from each star falls upon the other, and the result has to be carefully modeled to simulate the observed spectrum of the ...
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283 views

Can BY Draconis variable stars sustain any form of complex life?

I wanted to ask this, because while I was working on two fictional planets back on the Worldbuilding SE, one of them being habitable, which orbit the 61 Cygni A star of the 61 Cygni binary star system,...
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1answer
159 views

Is it possible for two stars to be in a horseshoe orbit around a much larger star?

I was reading about how Saturn has two moons, Janus and Epimetheus, that swap orbits once every four years. Could something like this happen on a much larger scale, but with stars instead of a planet ...
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1answer
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Would 2 stars in binary star formation with same mass and no velocity collide into each other? [closed]

Velocity decides if 2 stars with different masses in a binary star formation will collide or not, but if 2 stars with same mass existed but with no velocity (i.e they are not orbiting each other, just ...
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3answers
2k views

Binaries consisting of a black hole and a non-black hole?

Are there any known binary systems in which one member is a black hole and the other is not a black hole (main sequence star, giant, neutron star, white dwarf, whatever)? Googling seems to turn up ...
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1answer
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How does a planet lose mass to its host star?

How do bodies like WASP-12b lose mass to its central body? The process is never really explained in popular media, instead showing visualisations of a thin veil of gas being "sucked" in a rather ...
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1answer
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What if a white dwarf is less massive than her partner?

For example: a system with a 0.2 solar mass white dwarf orbiting a 0.25 solar mass red dwarf. Does the red dwarf steals mass from the white dwarf or vice versa.
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Can a binary star optically “orbit” a planet?

I was watching a science fiction anime from the mid 70's. In it, there was a star orbiting a planet. Since this seemed impossible, and I had never heard of it, I looked on the internet to see if this ...
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1answer
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How Can I View KIC 9832227?

I've heard that KIC 9832227 is a contact binary star system that is expected to merge and explode as a "red nova" sometime in the next ~5 years or so. http://www.sciencemag.org/news/2017/01/colliding-...
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How are binary star systems created?

I don't know how common it is for a system to have two stars (or perhaps even more) but how do they arise? Is that due to the stellar accretion disc, or the composition of the stellar nebula? Or are ...
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Will Sirius B start accreting from A and become a supernova type Ia?

Sirius B is a massive white dwarf of 1 Solar mass, orbiting at about 25 AU distance from the 2 Solar mass Sirius A. As it evolves and expands, will the A star start shedding matter to the white dwarf, ...
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1answer
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Why does Sirius proper motion “wiggle” with a 1 year period, when Sirius A and Bs binary orbit is a 50 year period?

Some stars, if observed repeatedly over time, show a perturbation or "wobble" in their proper motion. If this is a periodic occurrence we can infer that the perturbation occurs due to the ...
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1answer
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What is the tidal radius of the Sirius system?

The Fomalhaut system is a trinary system, with Fomalhaut A (1.9 M), Fomalhaut B (0.7M) and Fomalhaut C (0.2M). Fomalhaut C is 2.5 light years from Fomalhaut A, and 3.2 light years away from Fomalhaut ...
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Which data should I use to take the fast Fourier transform (FFT) to find time period for eclipsing binaries?

I am trying to use Kepler Data for Eclipsing Binaries to estimate time period, and then other parameters such as mass, eccentricity, semi-major axis, distance, etc. of the system. I want to write code ...
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1answer
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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 ...
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2k views

Multiple Star-system percentages

What are the percentages of systems that have x number of stars in them? What I have found thus far is something like: Single Star Sytems = 69% Double Star Systems = ~10% Triple Star Systems = <...
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1answer
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V471 Tauri's circumbinary brown dwarf non-observation; Applegate, or over-restrictive assumptions?

tl;dr Has the brown dwarf observation been disproven? I have just started reading about the interesting object V471 Tauri. The first two sentences of the introduction to The V471 Tauri System: A ...