<p>Bayer didn't sort the stars strictly by brightness.  He classified them as &quot;first magnitude&quot;,  &quot;second magnitude&quot; (and so on) following the traditional magnitudes assigned to stars since ancient times.</p>
<p>Then he names the stars of the first magnitude <span class="math-container">$\alpha$</span>, <span class="math-container">$\beta$</span> etc. without attempting to distinguish the brightest star.  Sometimes he seems to have labeled the stars from East to West, or in order of rising, or from the &quot;head&quot; to the &quot;tail&quot; of the constellation. Sometimes his ordering seems to have been haphazard.</p>
<p>And he didn't always follow his own &quot;rules&quot;.  In Ursa Major, the stars are named in sequence along the &quot;dipper&quot;, not according to brightness.</p>

CC BY-SA 4.0
2023-06-21T13:20:24.723Z
Note that Ursa Major != the Big Dipper.  The dipper is just part of the larger constellation of Ursa Major, which contains about 10 other stars in addition to those that make up the dipper.
Darrel Hoffman
CC BY-SA 4.0
2023-06-20T16:45:55.590Z
2023-06-20T16:45:55.590Z
James K
<p>It's true that stars are lettered in order of brightness. So, in a constellation the brightnest star is (Alpha), the second brightest (Beta) and so on. That is why most of the <a href="http://www.stargazing.net/david/constel/brightstars.html" rel="noreferrer">First Magnitude Stars</a> are designated Alpha and a few are designated Beta. But there are cases where stars in a constellation have nearly the same brightness. In that case, they are lettered in order of their positions in the constellation, beginning at the head. For example, in the constellation of Ursa Major the bright stars are almost similar in brightness and therefore are lettered in order of postion from the head to the ladle.</p>
<p><a href="https://i.sstatic.net/7Ayh8.jpg" rel="noreferrer"><img src="https://i.sstatic.net/7Ayh8.jpg" alt="enter image description here" /></a></p>
<p>You can check <a href="https://en.wikipedia.org/wiki/Bayer_designation" rel="noreferrer">Bayer designation</a> for more information.</p>
<p>References</p>
<ol>
<li><p><a href="http://www.stargazing.net/david/constel/greek.html" rel="noreferrer">http://www.stargazing.net/david/constel/greek.html</a></p>
</li>
<li><p><a href="https://skyandtelescope.org/astronomy-resources/the-greek-alphabet/" rel="noreferrer">https://skyandtelescope.org/astronomy-resources/the-greek-alphabet/</a></p>
</li>
</ol>

CC BY-SA 4.0
2023-06-20T16:15:50.130Z
2023-06-20T16:15:50.130Z
Nilay Ghosh
<p>From the Wikipedia page of <a href="https://en.wikipedia.org/wiki/Alpha_Ursae_Majoris" rel="noreferrer">Alpha Ursae Majoris</a>:</p>
<blockquote>
<p>Alpha Ursae Majoris, Latinised from α Ursae Majoris, formally named Dubhe /ˈdʌbiː/, is, despite being designated &quot;α&quot; (alpha), the second-brightest object in the northern constellation of Ursa Major.</p>
</blockquote>
<p>From the Wikipedia page of <a href="https://en.wikipedia.org/wiki/Epsilon_Ursae_Majoris" rel="noreferrer">Epsilon Ursae Majoris</a>:</p>
<blockquote>
<p>Despite being designated &quot;ε&quot; (epsilon), it is the brightest star in the constellation and at magnitude 1.77 is the thirty-third brightest star in the sky.</p>
</blockquote>
<p>Why are sometimes the brightest star of a constellation not named Alpha? How many constellations are there with this naming exception?</p>

CC BY-SA 4.0
2023-06-20T15:42:10.720Z
Good question (+1). Yet have you read e.g. https://en.wikipedia.org/wiki/Bayer_designation ?
planetmaker
CC BY-SA 4.0
2023-06-20T15:55:29.803Z
Thank you. That Wikipedia article helped a lot.
Snack Exchange
<star><constellations><naming><brightness>
Why are sometimes the brightest star of a constellation not named alpha?
Snack Exchange
# Why are sometimes the brightest star of a constellation not named alpha?

(Asked by: username_0 on 2023-06-20)

From the Wikipedia page of [Alpha Ursae Majoris](https://en.wikipedia.org/wiki/Alpha_Ursae_Majoris):

> Alpha Ursae Majoris, Latinised from α Ursae Majoris, formally named Dubhe /ˈdʌbiː/, is, despite being designated "α" (alpha), the second-brightest object in the northern constellation of Ursa Major.

From the Wikipedia page of [Epsilon Ursae Majoris](https://en.wikipedia.org/wiki/Epsilon_Ursae_Majoris):

> Despite being designated "ε" (epsilon), it is the brightest star in the constellation and at magnitude 1.77 is the thirty-third brightest star in the sky.

Why are sometimes the brightest star of a constellation not named Alpha? How many constellations are there with this naming exception?

**Tags:** star, constellations, naming, brightness
> **Comments:**
> **username_1**: Good question (+1). Yet have you read e.g. https://en.wikipedia.org/wiki/Bayer_designation ?  
> **username_0**: Thank you. That Wikipedia article helped a lot.  

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## 2 answers

### Answer by username_4 on 2023-06-20. Score: 9 | Accepted answer

It's true that stars are lettered in order of brightness. So, in a constellation the brightnest star is (Alpha), the second brightest (Beta) and so on. That is why most of the [First Magnitude Stars](http://www.stargazing.net/david/constel/brightstars.html) are designated Alpha and a few are designated Beta. But there are cases where stars in a constellation have nearly the same brightness. In that case, they are lettered in order of their positions in the constellation, beginning at the head. For example, in the constellation of Ursa Major the bright stars are almost similar in brightness and therefore are lettered in order of postion from the head to the ladle.

[![enter image description here](https://i.sstatic.net/7Ayh8.jpg)](https://i.sstatic.net/7Ayh8.jpg)

You can check [Bayer designation](https://en.wikipedia.org/wiki/Bayer_designation) for more information.

References

1. <http://www.stargazing.net/david/constel/greek.html>
2. <https://skyandtelescope.org/astronomy-resources/the-greek-alphabet/>


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### Answer by username_2 on 2023-06-20. Score: 24

Bayer didn't sort the stars strictly by brightness. He classified them as "first magnitude", "second magnitude" (and so on) following the traditional magnitudes assigned to stars since ancient times.

Then he names the stars of the first magnitude $\alpha$, $\beta$ etc. without attempting to distinguish the brightest star. Sometimes he seems to have labeled the stars from East to West, or in order of rising, or from the "head" to the "tail" of the constellation. Sometimes his ordering seems to have been haphazard.

And he didn't always follow his own "rules". In Ursa Major, the stars are named in sequence along the "dipper", not according to brightness.

> **Comments:**
> **username_3**: Note that Ursa Major != the Big Dipper.  The dipper is just part of the larger constellation of Ursa Major, which contains about 10 other stars in addition to those that make up the dipper.  

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