<div class="s-table-container">
<table class="s-table">
<thead>
<tr>
<th>Luminosity class \ Spectral type</th>
<th>O</th>
<th>B</th>
<th>A</th>
<th>F</th>
<th>G</th>
<th>K</th>
<th>M</th>
<th>All</th>
</tr>
</thead>
<tbody>
<tr>
<td>Main Sequence (V,VI)</td>
<td>0.000029%</td>
<td>0.12%</td>
<td>0.59%</td>
<td>2.9%</td>
<td>7.3%</td>
<td>12%</td>
<td>73.5%</td>
<td><strong>93%</strong></td>
</tr>
<tr>
<td>Giant (I-IV)</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>0.5%</td>
<td>0.5%</td>
<td><strong>1%</strong></td>
</tr>
<tr>
<td>White Dwarf</td>
<td></td>
<td></td>
<td>0.5%</td>
<td>1.5%</td>
<td>1.5%</td>
<td>1.5%</td>
<td>1%</td>
<td><strong>6%</strong></td>
</tr>
<tr>
<td>Total</td>
<td>0.000029%</td>
<td>0.12%</td>
<td>1.09%</td>
<td>4.5%</td>
<td>8.8%</td>
<td>14%</td>
<td>75%</td>
<td>100%</td>
</tr>
</tbody>
</table>
</div>
<p>This is very rough:  What I've done is used the classification into Main sequence/Giant/White dwarf from <a href="https://astronomy.stackexchange.com/questions/13165/what-is-the-frequency-distribution-for-luminosity-classes-in-the-milky-way-galax">What is the frequency distribution for luminosity classes in the Milky Way Galaxy?</a> and the distribution for stars in the main sequence from Wikipedia. So, for example 3.1% of main sequence stars are F type, and 93% of stars are main sequence, then about 2.9% of stars are main sequence F-type stars.  I've then eyeballed the distribution of Giants and White dwarf stars from the graphs on the linked question.</p>
<p>I've then added up and tried to make the numbers make 100%. This is probably a start, but not the final word, so I'll make the a CW.</p>
<p>The main takeaway is that most stars are small dim and reddish, they are red dwarfs - but none of these are visible with the naked eye. Most of the naked eye stars are B,A,F type, or K and M type giants, as these are visible across many light years.</p>

CC BY-SA 4.0
2023-06-03T19:01:42.617Z
2023-06-03T20:58:42.890Z
2023-06-03T20:58:42.890Z
James K
<p>I am a programming tutor, and with my student we were writing a program simulating a flight through the cosmos.</p>
<p>I thought that it would be great to make the circles representing stars more realistic. I have found <a href="http://www.isthe.com/chongo/tech/astro/HR-temp-mass-table-byhrclass.html" rel="nofollow noreferrer">the table showing size and colour</a> of a star by its stellar type, but what is the probability that any given star is going to be of a specific type?1 The simple solution would be to just to select at random from the list, but that is too trivial.</p>
<p>If there would be some data showing the total counts of stars by the type, it would be trivial to convert into the probability. But i cannot find such.</p>

CC BY-SA 4.0
2023-06-03T14:44:03.120Z
https://astronomy.stackexchange.com/questions/13165/what-is-the-frequency-distribution-for-luminosity-classes-in-the-milky-way-galax  Is a close match,  Can you find an answer there?
James K
CC BY-SA 4.0
2023-06-03T14:45:06.880Z
Perhaps not... that is about luminosity classes, not OBAFGKM class.  But it does lead to this Wikipedia page https://en.wikipedia.org/wiki/Stellar_classification#Harvard_spectral_classification
James K
<star><spectral-type>
What are probabilities of finding a star with the specific stellar type?
v010dya
# What are probabilities of finding a star with the specific stellar type?

(Asked by: username_0 on 2023-06-03)

I am a programming tutor, and with my student we were writing a program simulating a flight through the cosmos.

I thought that it would be great to make the circles representing stars more realistic. I have found [the table showing size and colour](http://www.isthe.com/chongo/tech/astro/HR-temp-mass-table-byhrclass.html) of a star by its stellar type, but what is the probability that any given star is going to be of a specific type?1 The simple solution would be to just to select at random from the list, but that is too trivial.

If there would be some data showing the total counts of stars by the type, it would be trivial to convert into the probability. But i cannot find such.

**Tags:** star, spectral-type

> **Comments:**
> **username_1**: https://astronomy.stackexchange.com/questions/13165/what-is-the-frequency-distribution-for-luminosity-classes-in-the-milky-way-galax  Is a close match,  Can you find an answer there?  
> **username_1**: Perhaps not... that is about luminosity classes, not OBAFGKM class.  But it does lead to this Wikipedia page https://en.wikipedia.org/wiki/Stellar_classification#Harvard_spectral_classification  

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## 1 answers

### Answer by username_1 on 2023-06-03. Score: 2 | Accepted answer

| Luminosity class \ Spectral type | O | B | A | F | G | K | M | All |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Main Sequence (V,VI) | 0.000029% | 0.12% | 0.59% | 2.9% | 7.3% | 12% | 73.5% | **93%** |
| Giant (I-IV) |  |  |  |  |  | 0.5% | 0.5% | **1%** |
| White Dwarf |  |  | 0.5% | 1.5% | 1.5% | 1.5% | 1% | **6%** |
| Total | 0.000029% | 0.12% | 1.09% | 4.5% | 8.8% | 14% | 75% | 100% |

This is very rough: What I've done is used the classification into Main sequence/Giant/White dwarf from [What is the frequency distribution for luminosity classes in the Milky Way Galaxy?](https://astronomy.stackexchange.com/questions/13165/what-is-the-frequency-distribution-for-luminosity-classes-in-the-milky-way-galax) and the distribution for stars in the main sequence from Wikipedia. So, for example 3.1% of main sequence stars are F type, and 93% of stars are main sequence, then about 2.9% of stars are main sequence F-type stars. I've then eyeballed the distribution of Giants and White dwarf stars from the graphs on the linked question.

I've then added up and tried to make the numbers make 100%. This is probably a start, but not the final word, so I'll make the a CW.

The main takeaway is that most stars are small dim and reddish, they are red dwarfs - but none of these are visible with the naked eye. Most of the naked eye stars are B,A,F type, or K and M type giants, as these are visible across many light years.


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