Re: OBAFGKM

Donn, Lynne, Rogelio...

Thanks for the explanation and links, but I don't think it answers my
real question. Here are the spectral classes and temp:

O > 28,000K
B 28,000 - 10,000K
A 10,000 - 7,500K
F 7,500 - 6,000K
G 6,000 - 5,000K
K 5,000 - 3,500K
M < 3,500K

So, why is the O star assigned the letter O? I understand O represents
a temperature range, but why the letter O?

Donn Mukensnable wrote:
> Originally, the stellar classes were ABCD...etc. but around the time
> of Hertzsprung, the true temperatures of stars was determined and the
> classification order, but not the letters, was adjusted. Who said
> astronomers were eager for change? heh
>
> Oh, and don't ask me about Population II stars...
>
>
> Donn
>
>
> On 24 Aug, 2009, at 15:02, Mark Wagner wrote:
>
>>
>> The basic mnenomic for stellar types.
>>
>> I was telling a woman about this today, and she wanted to know why
>> the stellar types have the letters they do.
>>
>> I was stumped.
>>
>> Anyone know how the types of stars were assigned their letters?
>>
>> Mark
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