<p><a href="https://en.wikipedia.org/wiki/Mu_Sagittarii" rel="noreferrer">Mu Sagittarii</a> is a star system, not a single star. If that can be included, then <a href="https://en.wikipedia.org/wiki/Eta_Carinae" rel="noreferrer">Eta Carinae</a> should be included, and it has an absolute magnitude of -12.0. It's a star system about 7,500 light-years from Earth.</p>

<p>It looks like the brightest (absolute magnitude) single star visible to the unaided eye is WR 24 (in Carina Nebula). Its absolute magnitude is −11.1 and apparent magnitude is 6.48, so just barely visible.</p>

<p>source: <a href="https://en.wikipedia.org/wiki/List_of_most_luminous_known_stars" rel="noreferrer">Wikipedia - List of most luminous known stars</a></p>

<p>edit: <a href="https://en.wikipedia.org/wiki/Rho_Cassiopeiae#cite_note-gorlova-6" rel="noreferrer">Rho Cassiopeiae</a>'s absolute magnitude is -9.5.</p>

CC BY-SA 3.0
2015-06-30T21:58:01.737Z
2015-06-30T22:09:06.787Z
2015-06-30T22:09:06.787Z
duzzy
<p>Is it <a href="https://en.wikipedia.org/wiki/Rho_Cassiopeiae" rel="nofollow">Rho Cassiopeiae</a> or <a href="https://en.wikipedia.org/wiki/Mu_Sagittarii" rel="nofollow">Mu Sagittarii</a>?<br>
I see in the <a href="https://launchpad.net/stellarium/+milestone/0.13.0" rel="nofollow">Stellarium 0.13.0</a> that Mu Sagittarii has absolute magnitude -11.43!!</p>

CC BY-SA 3.0
2016-04-09T12:11:29.090Z
We should include variable stars and supernovae, right?
Johannes
CC BY-SA 3.0
2016-04-09T13:21:05.620Z
@Johannes supernova?! Of course not. Only stars, this contains variable stars.
Ab_Sh
CC BY-SA 3.0
2016-04-09T16:37:16.533Z
@2000 - a supernova is a highly variable star, isn't it?
Johannes
CC BY-SA 3.0
2016-04-09T17:04:40.927Z
@Johannes From [Wikipedia](https://en.wikipedia.org/wiki/Supernova): A supernova is an astronomical **event** that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion. For a short time, this causes the sudden appearance of a 'new' bright star, before slowly fading from sight over several weeks or months.
Ab_Sh
CC BY-SA 3.0
2016-04-09T17:15:23.140Z
@2000 - yes, a supernova is an event in the life of a star, which causes a high variability in its luminosity (absolute magnitude).
Johannes
CC BY-SA 3.0
2015-07-02T18:17:24.747Z
The sun, obviously! But don't think you can look directly at it with the naked eye. Well, you could, but that might be the last thing you see ;).
rubenvb
CC BY-SA 3.0
2015-07-02T20:06:48.310Z
No, the absolute magnitude of the Sun is only around 4.75.
ProfRob
CC BY-SA 3.0
2015-07-02T20:43:53.223Z
You should see [Absolute magnitude](https://en.wikipedia.org/wiki/Absolute_magnitude)
Ab_Sh
CC BY-SA 3.0
2015-07-02T20:51:44.980Z
Right bad joke. Got it. This is how far I get under the influence of a heat wave ;). My mind missed the absolute magnitude part, cause I knew the term, just didn't register it...
rubenvb
<star><magnitude>
What is the brightest star (by absolute magnitude) that we can see by naked eye?
Ab_Sh
# What is the brightest star (by absolute magnitude) that we can see by naked eye?

(Asked by: username_0 on 2015-06-30)

Is it [Rho Cassiopeiae](https://en.wikipedia.org/wiki/Rho_Cassiopeiae) or [Mu Sagittarii](https://en.wikipedia.org/wiki/Mu_Sagittarii)?  
I see in the [Stellarium 0.13.0](https://launchpad.net/stellarium/+milestone/0.13.0) that Mu Sagittarii has absolute magnitude -11.43!!

**Tags:** star, magnitude

> **Comments:**
> **username_2**: The sun, obviously! But don't think you can look directly at it with the naked eye. Well, you could, but that might be the last thing you see ;).  
> **username_3**: No, the absolute magnitude of the Sun is only around 4.75.  
> **username_0**: You should see [Absolute magnitude](https://en.wikipedia.org/wiki/Absolute_magnitude)  
> **username_2**: Right bad joke. Got it. This is how far I get under the influence of a heat wave ;). My mind missed the absolute magnitude part, cause I knew the term, just didn't register it...  
> **username_1**: We should include variable stars and supernovae, right?  
> **username_0**: @username_1 supernova?! Of course not. Only stars, this contains variable stars.  
> **username_1**: @2000 - a supernova is a highly variable star, isn't it?  
> **username_0**: @username_1 From [Wikipedia](https://en.wikipedia.org/wiki/Supernova): A supernova is an astronomical **event** that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion. For a short time, this causes the sudden appearance of a 'new' bright star, before slowly fading from sight over several weeks or months.  
> **username_1**: @2000 - yes, a supernova is an event in the life of a star, which causes a high variability in its luminosity (absolute magnitude).  

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## 1 answers

### Answer by username_4 on 2015-06-30. Score: 5 | Accepted answer

[Mu Sagittarii](https://en.wikipedia.org/wiki/Mu_Sagittarii) is a star system, not a single star. If that can be included, then [Eta Carinae](https://en.wikipedia.org/wiki/Eta_Carinae) should be included, and it has an absolute magnitude of -12.0. It's a star system about 7,500 light-years from Earth.

It looks like the brightest (absolute magnitude) single star visible to the unaided eye is WR 24 (in Carina Nebula). Its absolute magnitude is −11.1 and apparent magnitude is 6.48, so just barely visible.

source: [Wikipedia - List of most luminous known stars](https://en.wikipedia.org/wiki/List_of_most_luminous_known_stars)

edit: [Rho Cassiopeiae](https://en.wikipedia.org/wiki/Rho_Cassiopeiae#cite_note-gorlova-6)'s absolute magnitude is -9.5.


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