<p>No, it is correct. The inclination of an <em>eclipsing</em> binary can be estimated from the light curve (and is likely to be close to 90 degrees in order to produce an eclipse).</p>
<p>The radial velocity curves can then give <span class="math-container">$M_{1,2}\sin(i)$</span> and hence the component masses.</p>

CC BY-SA 4.0
2021-08-30T09:23:39.240Z
2021-08-30T09:23:39.240Z
ProfRob
<p>Is the statement</p>
<blockquote>
<p>From radial velocities or astrometry for eclipsing binaries, one obtains masses.</p>
</blockquote>
<p>wrong, because only minimal masses can be obtained?</p>

CC BY-SA 4.0
2021-08-30T06:39:32.393Z
What is the source of the statement, please.
James K
CC BY-SA 4.0
2021-08-30T06:56:30.270Z
"one obtains masses" is a very vague statement. It can also refer to minimal masses I guess.
prody
CC BY-SA 4.0
2021-08-30T07:18:20.987Z
Thus, 

    'From RVs or astrometry for eclipsing binaries, one obtains minimal masses.' is correct?
Anna-Kat
CC BY-SA 4.0
2021-08-30T07:25:00.803Z
Radial velocities
Anna-Kat
CC BY-SA 4.0
2021-08-30T08:17:30.137Z
I find it difficult to judge the absolute truth of such short and out of context statements that you are asking also in other questions. I really think it could help if you provided more context. In this case the statement may be correct because if the binaries are eclipsing then the $\sin i$ degeneracy is broken and one can obtain the true masses
Prallax
<observational-astronomy><radial-velocity><eclipsing-star-systems>
Determining masses from radial velocity curves of eclipsing binaries
Anna-Kat
# Determining masses from radial velocity curves of eclipsing binaries

(Asked by: username_0 on 2021-08-30)

Is the statement

> From radial velocities or astrometry for eclipsing binaries, one obtains masses.

wrong, because only minimal masses can be obtained?

**Tags:** observational-astronomy, radial-velocity, eclipsing-star-systems
> **Comments:**
> **username_1**: What is the source of the statement, please.  
> **username_2**: "one obtains masses" is a very vague statement. It can also refer to minimal masses I guess.  
> **username_0**: Thus,       'From RVs or astrometry for eclipsing binaries, one obtains minimal masses.' is correct?  
> **username_0**: Radial velocities  
> **username_3**: I find it difficult to judge the absolute truth of such short and out of context statements that you are asking also in other questions. I really think it could help if you provided more context. In this case the statement may be correct because if the binaries are eclipsing then the $\sin i$ degeneracy is broken and one can obtain the true masses  

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## 1 answers

### Answer by username_4 on 2021-08-30. Score: 2 | Accepted answer

No, it is correct. The inclination of an *eclipsing* binary can be estimated from the light curve (and is likely to be close to 90 degrees in order to produce an eclipse).

The radial velocity curves can then give $M\_{1,2}\sin(i)$ and hence the component masses.


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