<p>The Variable stars that Hubble studied in M31 when he showed that it was a galaxy are among the most luminous. They include Var-A1, a luminous blue variable, and <a href="http://arxiv.org/pdf/1403.6859.pdf" rel="nofollow">magnitude about 16.5</a>. Var A-1 is one of the most luminous stars known.</p>

<p>Nasa has a <a href="http://heasarc.gsfc.nasa.gov/W3Browse/star-catalog/m31stars.html" rel="nofollow">catalog of stars</a> in the m31 field, The brightest star in this catalog is an <a href="http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%401560657&amp;Name=TYC%202788-276-1&amp;submit=submit" rel="nofollow">11.4 magnitude</a> star. But I think that database needs careful interpretation.</p>

CC BY-SA 3.0
2015-09-29T21:41:13.003Z
2015-09-29T21:41:13.003Z
James K
<p>I am wondering what the brightest individual star is in M31, the Andromeda Galaxy.  Specifically, brightest as seen from Earth (so relative magnitude).</p>

CC BY-SA 3.0
2015-09-29T17:26:04.053Z
Yes, I am discounting supernovae.  I am specifically wondering about stars Gaia could look at (so, ideally will be visible over a 5 year period).
NeutronStar
<star><apparent-magnitude><magnitude><hypergiants><m31>
What is the brightest star (relative magnitude) in M31?
NeutronStar
# What is the brightest star (relative magnitude) in M31?

(Asked by: username_0 on 2015-09-28)

I am wondering what the brightest individual star is in M31, the Andromeda Galaxy. Specifically, brightest as seen from Earth (so relative magnitude).

**Tags:** star, apparent-magnitude, magnitude, hypergiants, m31

> **Comments:**
> **username_0**: Yes, I am discounting supernovae.  I am specifically wondering about stars Gaia could look at (so, ideally will be visible over a 5 year period).  

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## 1 answers

### Answer by username_1 on 2015-09-29. Score: 2 | Accepted answer

The Variable stars that Hubble studied in M31 when he showed that it was a galaxy are among the most luminous. They include Var-A1, a luminous blue variable, and [magnitude about 16.5](http://arxiv.org/pdf/1403.6859.pdf). Var A-1 is one of the most luminous stars known.

Nasa has a [catalog of stars](http://heasarc.gsfc.nasa.gov/W3Browse/star-catalog/m31stars.html) in the m31 field, The brightest star in this catalog is an [11.4 magnitude](http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%401560657&Name=TYC%202788-276-1&submit=submit) star. But I think that database needs careful interpretation.


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