Questions tagged [binary-star]

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

Filter by
Sorted by
Tagged with
0
votes
1answer
55 views

Orbit of Luhman 16?

I am studying some binary stars and brown dwarfs. Some orbits are known and easy to find, like Alpha Centauri. However, when I look for the orbital characteristics of Luhman 16 (AB), I only get the ...
5
votes
1answer
98 views

Which binary star system has a greatest angular distance?

Visible from the Earth, which binary star system has greatest angular distance ?
1
vote
0answers
47 views

Visual binary star with circular apparent orbit

Does anyone know a good example of visual (or interferometric) binary star apparent orbit of which looks circular due to projection though in fact is markedly elliptical? I need that for teaching.
5
votes
1answer
92 views

Fate of a planet orbiting a Lagrange point behind a star?

Let's say there is a planet orbiting at L5 behind a star, which is in turn orbiting a more massive star, like so: What is the ultimate fate of this planet? I'm predicting that it will spiral into the ...
1
vote
2answers
59 views

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

Recently it has been shown that a large number of binary stellar systems exist. It seems to me that the orbits of stars in systems containing three or more stars will inevitably be chaotic, resulting ...
2
votes
0answers
21 views

Relation between inner and outer eccentricities in a hierarchical triple star system

According to Table 3 of Sterzik & Tokovinin (2002), the inner eccentricity of a triple star system (i.e. the eccentricity of the inner binary) is, most of the times (70%), larger than the outer ...
1
vote
2answers
54 views

What is the lifetime of an x-ray binary?

What would be the typical lifetime of an x-ray binary? I have trouble finding a reference.
1
vote
0answers
11 views

What is the relation between between hardness ratio(HR) and spectral state of a X-ray binary star system?

When reading about hardness ratio, it shows that depending on the hardness ratio spectral states of a binary star can be divided into soft, hard states. So how the HR value changes with respect to the ...
4
votes
1answer
93 views

Any known Triple Star Systems with this hierarchy?

I'm curious, are there any known STABLE triple systems in which a close inner binary pair is orbited by a more massive star, yet the total mass of the binary pair is greater than that single orbiting ...
4
votes
1answer
36 views

Interaction of stellar winds in binary star systems

Binary star systems are fairly common but I am unable to find any information on how the stars interact with one another on aspects other than gravitational affects. Using Alpha Centauri as the ...
1
vote
2answers
48 views

Eta Cassiopeiae star type; G0V? F9V? Both?

For a story I am looking into the star system of Eta Cassiopeiae, which is a binary with a main sequence star called Achird (very similar to the sun) and a K7V star. The issue I am running into is the ...
1
vote
1answer
29 views

Is HR 5171 a Spectroscopic Binary or a Symbiotic?

Is HR 5171, the largest yellow star in the galaxy a symbiotic star where one feeds off the other? Or is it a spectroscopic binary where its only possible to determine that there are two stars by ...
3
votes
1answer
48 views

Origin as binaries and multiple system

The majority of hot stars originate as binaries or multiple systems. How is it with the cooler spectral types? Are they usually born as single stars?
4
votes
2answers
112 views

Probability of planets in binary star systems?

There is much fiction on binary stars with planets, for whatever reason, and this keeps supporting the popular impression that those systems are frequent. Indeed, the methods for identifying ...
4
votes
1answer
42 views

Is a double quasi-binary system valid?

I was messing around with 4-body problems, and discovered a system where a close binary and a regular binary pair orbit each other. The regular binary gets disrupted every few orbits and one star ...
1
vote
2answers
41 views

Naming convention for multiple star systems

Okay, so I've seen different notations for the stars in β Capricorni. Some sources state that the stars are Aa, Ab1 and Ab2, Ba, and Bb, while others say that they are Aa, Aba and Abb, Ba, and Bb. So, ...
1
vote
1answer
89 views

Calculate the absolute magnitude for a multi-star system

We know that the absolute magnitude of a single star can be calculated with the formulae: $$M_{\rm bol} = 4.75 -2.5 \log_{10} \left(\frac{L_*}{L_{\odot}}\right)\ ,$$ $$M = -2.5 \log_{10}(L_* / L_0),$$...
-1
votes
1answer
54 views

Is Adhara a member of binary star system?

During the initial days of Covid pandemic I discovered my interest in astronomy . I found it by gazing at night sky near Sirius that Adhara was undergoing a significant wobbling motion . I thought ...
0
votes
2answers
90 views

Question about orbital direction on binary systems

I wonder if is possible to find a binary system in which one star is orbiting the center of mass in one direction and the latter orbiting in the opposite direction. Would this transgress angular ...
4
votes
2answers
218 views

Calculating distance from center of mass of two stars in a binary system

I am confused on how to calculate the distances for each star in a binary system to their centre of mass. I am trying to solve it from a book I am reading which shows the solution but I do not ...
4
votes
1answer
45 views

Alfven Radius of mainsequence stars

Is there any average value for the Alfven radius of main-sequence stars? if there are no such values, then how may I calculate it??
9
votes
1answer
723 views

What do the words “p-type” and “s-type” mean?

As explained in various sources (such as that answer), a planet in an s-type orbit orbits one of the stars of a binary star system, whereas a planet in a p-type orbit orbits both stars. A synonym for ...
5
votes
1answer
318 views

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 ...
2
votes
1answer
49 views

Apparent Centering Problem When Using the Perifocal System to Draw Orbital Ellipses [closed]

I am attempting to render orbital ellipses in software. Given a set of orbital elements, I am using the Perifocal system to determine a set of points along the curve of the ellipse. I am using the ...
2
votes
2answers
145 views

Could there be a planet at the barycenter between two or more stars revolving around each other?

In binary star systems, could there be a planet the stars revolve around, with eternal day on all sides? 1st scenario: Imagine a binary system consisting of two Sunlike G5V stars of 1 solar mass each, ...
0
votes
1answer
83 views

Question about semi-major axis mean separation

I am currently doing an assignment but I cannot for the life of me understand what one of terms used means. Notice I am not trying to get help with the assignment itself, but rather to make me ...
4
votes
2answers
113 views

Binary Star Initial Speed

I am writing a 2D simulation for binary stars orbiting each other. Currently, the initial position of the stars are on opposite sides of the screen with the left star having a velocity up the page and ...
1
vote
0answers
39 views

Why are the W UMa variable subtypes labelled “A” and “W”?

The W Ursae Majoris variables (eclipsing contact binary stars) are divided into the A- and W-types. As described in Wilson (1978) "On the A-type W UMa systems": There are two recognized ...
0
votes
1answer
56 views

The definition of eclipsing binary star systems

In the second minimum (the 3rd step) there is a smaller decrease in light intensity. For this to happen, wouldn't you need to be looking at the plane of orbit from above rather than directly along the ...
2
votes
1answer
170 views

Fractional contribution of secondary star

What do we mean by "the luminosity fraction" and "the fractional contribution of the secondary star" of binary stars? can anyone suggest any method to calculate them theoretically?...
1
vote
0answers
85 views

6th catalogue of orbits of visual binary stars

I wanted to download or access the US navy catalog " the sixth catalog of orbits of visual binaries". I have already tried USNO web site and vizier. but I couldn't see them there. The link was dead ...
4
votes
0answers
37 views

Is Beta Lyrae still thought to be losing mass in a spiral outflow?

In the famous 1960 painting by Chesley Bonestell, Beta Lyrae is depicted with a glowing spiral trail of matter emanating from the binary stars. I'm wondering if that's still thought to be a ...
0
votes
1answer
50 views

Binary star data

I was doing a project on Binary stars. I wanted data of masses, eccentricity, semi-major axis, and radial velocity. I tried many sites but I couldn't find them. Where can I download such data from?
0
votes
0answers
15 views

Radial velocity data in ALADIN or TOPCAT for Binary Systems

I just installed both, Aladin and Topcat VO tools. I want to know how to search for: HD 226868 and A0620-00 radial velocity data or photometric curves to derive the hidden black hole mass in those ...
1
vote
0answers
48 views

Binary stars and gas giant formation

Say there's a young s-type binary star system with 2 Sun-like stars. From what I understand for a stable orbit to be possible, a planet's farthest orbital point from its host star has to be around 1/5 ...
4
votes
1answer
184 views

Total apparent magnitude of eclipsing binary system

This is a question from the 2016 USAAAO national exam, for which no solutions are given: An eclipsing binary system has a magnitude $m_p$ = 14.2 during the primary transit and $m_s$ = 13.7 during ...
3
votes
0answers
95 views

Combined mass of binary stars

This is Question 17 from USAAAO Practice Round 2015. The answer is D. It would be best if someone can detail out the workings. In a nearby star system, two stars are seen to orbit each other every ...
2
votes
0answers
48 views

PHOEBE 2.2 Documentation, components and semi-major axis definitions

I'm looking at PHOEBE 2.2 Documentation, specifically at a tutorial about constraints What are Constraints? Constraints live in their own context of the Bundle, and many are created by default - ...
0
votes
0answers
36 views

Binary star system effects at the barycenter

I haven't been able to find anything on this so far. Using Alpha Centauri as the study, what events/effects ( if any ) would happen between the two stars? More specifically, between the gravitational ...
1
vote
0answers
53 views

Binary planet orbital distance

From reading various sources online, I see that some people talk about binary planets in very tight orbits (around 1 or 2 planet radii). I am wondering if it is possible for a binary planet (Double ...
1
vote
1answer
119 views

Why do they think that WDJ0551+4135 is “snowman shaped” i.e. a contact binary?

The BBC's Huge 'space snowman' is two merging stars says Researchers have discovered a huge snowman-shaped star with an atmospheric composition never seen before. It is more massive than our Sun but ...
1
vote
0answers
21 views

How to get data on Low mass x-ray binaries in M31 (Andromeda) Galaxy?

So my question is pretty straight forward, I am currently working on a project on finding X-ray emission counterparts for optically observable objects and was trying to get data on Low mass x-ray ...
0
votes
1answer
56 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. ...
2
votes
1answer
287 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.
1
vote
1answer
54 views

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 ...
4
votes
2answers
184 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 ...
28
votes
1answer
5k views

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 (...
29
votes
3answers
5k views

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? ...
4
votes
1answer
99 views

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 ...
5
votes
1answer
150 views

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 ...