<p>Where can I get a more detailed breakdown of Spectral Classes.  Wikipedia only has it at Letter level rather than sublevel. </p>

<p>For example, <a href="https://en.wikipedia.org/wiki/Stellar_classification" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Stellar_classification</a> has B ranging from 10,000 - 30,000K.  B0 is different to a B9, what would be the temperature range for a B0 or a B9 but not limiting to B but for all letters?</p>

<p>I'm not just looking at Temperature, I'm after Mass, Radius, Luminosity, Hydrogen Lines etc.</p>

<p>The closest that I've come is <a href="https://sites.uni.edu/morgans/astro/course/Notes/section2/spectraltemps.html" rel="nofollow noreferrer">https://sites.uni.edu/morgans/astro/course/Notes/section2/spectraltemps.html</a>  but it doesn't mention types II or IV and doesn't have Radius or Mass.</p>

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2019-10-11T22:54:27.347Z
Spectral type is connected with position in the HR diagram, there is no direct or one-to-one mapping with mass, except perhaps approximately on the main sequence, and even then it would be age and composition dependent.
ProfRob
<star><spectral-type>
Spectral Class Breakdown
MiscellaneousUser
# Spectral Class Breakdown

(Asked by: username_0 on 2019-10-11)

Where can I get a more detailed breakdown of Spectral Classes. Wikipedia only has it at Letter level rather than sublevel.

For example, <https://en.wikipedia.org/wiki/Stellar_classification> has B ranging from 10,000 - 30,000K. B0 is different to a B9, what would be the temperature range for a B0 or a B9 but not limiting to B but for all letters?

I'm not just looking at Temperature, I'm after Mass, Radius, Luminosity, Hydrogen Lines etc.

The closest that I've come is <https://sites.uni.edu/morgans/astro/course/Notes/section2/spectraltemps.html> but it doesn't mention types II or IV and doesn't have Radius or Mass.

**Tags:** star, spectral-type

> **Comments:**
> **username_1**: Spectral type is connected with position in the HR diagram, there is no direct or one-to-one mapping with mass, except perhaps approximately on the main sequence, and even then it would be age and composition dependent.  

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## 0 answers

