<p>I found <a href="https://arxiv.org/abs/1401.2628v2" rel="nofollow noreferrer">arXiv:1401.2628</a> which says</p>
<blockquote>
<p>Modeling the light curve with the NIGHTFALL program provides clear evidence that the system is a contact or possibly over-contact eclipsing binary. A total current system mass of <span class="math-container">$39^{+40}_{-22}$</span> solar mass and a high mass ratio <span class="math-container">$ q&gt;10$</span> is inferred for the system. The low-mass companion of <span class="math-container">${\rm HR5171 A}$</span> is very close to the primary star that is embedded within its dense wind. Tight constraints on the inclination and vsini of the primary are lacking, which prevents us from determining its influence precisely on the mass-loss phenomenon, but the system is probably experiencing a wind Roche-Lobe overflow.</p>
</blockquote>
<p>Does the need for simulation indicate that it is a <em>spectroscopic binary</em>?</p>

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2021-01-17T10:40:18.877Z
@ProfRob I am sure you know thr answer - please feel free to criticise my answer
B--rian
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2021-09-28T22:23:22.740Z
You might not have known in January that your `@` doesn't send a notification unless that user has commented here first (or has edited your post). If you'd like to "request a ProfRob review" you'll have to leave a comment where they have already commented, or under one of their other posts.
uhoh
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2021-01-01T14:28:56.117Z
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2021-01-01T14:43:45.907Z
B--rian
<p>Is <a href="https://en.wikipedia.org/wiki/HR_5171" rel="nofollow noreferrer">HR 5171</a>, the largest yellow star in the galaxy a <em><a href="https://en.wikipedia.org/wiki/Symbiotic_binary" rel="nofollow noreferrer">symbiotic star</a></em> where one feeds off the other? Or is it a <em>spectroscopic binary</em> where its only possible to determine that there are two stars by spectral analysis?</p>
<p>Will the smaller be consumed by the larger one as was in the possible case of BP Piscium? Or is the smaller one being born?</p>
<p>Is the star both, one or the other or neither?</p>
<p>I looked at <a href="http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Hr%205171" rel="nofollow noreferrer">Simbad</a> but it only calls a Double or Multiple Star System. That is too vague for me.  Calling it a Close Contact Binary is also too vague.  I know they call it an EBS.</p>
<p>If anyone wants an idea of the star, visit the <a href="http://www.sci-news.com/astronomy/science-hr5171a-largest-yellow-hypergiant-star-01802.html" rel="nofollow noreferrer">following artist's impression</a>.</p>

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2021-01-01T14:18:51.743Z
I slightly edited your question to make it easier to read, hope you agree with my suggestions. Also +1 :-)
B--rian
<star><binary-star>
Is HR 5171 a Spectroscopic Binary or a Symbiotic?
MiscellaneousUser
# Is HR 5171 a Spectroscopic Binary or a Symbiotic?

(Asked by: username_0 on 2021-01-01)

Is [HR 5171](https://en.wikipedia.org/wiki/HR_5171), the largest yellow star in the galaxy a *[symbiotic star](https://en.wikipedia.org/wiki/Symbiotic_binary)* where one feeds off the other? Or is it a *spectroscopic binary* where its only possible to determine that there are two stars by spectral analysis?

Will the smaller be consumed by the larger one as was in the possible case of BP Piscium? Or is the smaller one being born?

Is the star both, one or the other or neither?

I looked at [Simbad](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Hr%205171) but it only calls a Double or Multiple Star System. That is too vague for me. Calling it a Close Contact Binary is also too vague. I know they call it an EBS.

If anyone wants an idea of the star, visit the [following artist's impression](http://www.sci-news.com/astronomy/science-hr5171a-largest-yellow-hypergiant-star-01802.html).

**Tags:** star, binary-star
> **Comments:**
> **username_1**: I slightly edited your question to make it easier to read, hope you agree with my suggestions. Also +1 :-)  

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## 1 answers

### Answer by username_1 on 2021-01-01. Score: 1

I found [arXiv:1401.2628](https://arxiv.org/abs/1401.2628v2) which says

> Modeling the light curve with the NIGHTFALL program provides clear evidence that the system is a contact or possibly over-contact eclipsing binary. A total current system mass of $39^{+40}\_{-22}$ solar mass and a high mass ratio $ q>10$ is inferred for the system. The low-mass companion of ${\rm HR5171 A}$ is very close to the primary star that is embedded within its dense wind. Tight constraints on the inclination and vsini of the primary are lacking, which prevents us from determining its influence precisely on the mass-loss phenomenon, but the system is probably experiencing a wind Roche-Lobe overflow.

Does the need for simulation indicate that it is a *spectroscopic binary*?

> **Comments:**
> **username_1**: @ProfRob I am sure you know thr answer - please feel free to criticise my answer  
> **username_2**: You might not have known in January that your `@` doesn't send a notification unless that user has commented here first (or has edited your post). If you'd like to "request a ProfRob review" you'll have to leave a comment where they have already commented, or under one of their other posts.  

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