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Kaptain K
2002-Mar-09, 11:10 AM
In the April 2002 issue, in the article "Exploring the Bowl of the Big Dipper", the surface temperature of the star Megrez (Delta Ursae Majoris) is stated to be "9 to 10 million K" /phpBB/images/smiles/icon_rolleyes.gif /phpBB/images/smiles/icon_evil.gif

I had been trying to decide whether to subscribe to "Astronomy" or "Sky & Telescope". That the staff could let anything so blatantly wrong reach print decided the issue. /phpBB/images/smiles/icon_smile.gif

Hale_Bopp
2002-Mar-09, 02:52 PM
Darn...I just read that and you beat me to it /phpBB/images/smiles/icon_smile.gif

Need something hotter than an O type star for this one!

Rob

Russ
2002-Mar-18, 01:45 PM
OK, now that you've pointed out the error, how about telling us uninformed types what the correct numbers are. /phpBB/images/smiles/icon_smile.gif

Jim
2002-Mar-18, 02:47 PM
On 2002-03-18 08:45, Russ wrote:
OK, now that you've pointed out the error, how about telling us uninformed types what the correct numbers are. /phpBB/images/smiles/icon_smile.gif


Megrez is a class A white star. Class A stars run 7-10,000K; Megrez is A3, ~8,600K.

Class O stars top out at 60,000K.

Could they have meant internal temp?

Hale_Bopp
2002-Mar-18, 02:50 PM
Well, I have several astronomy books that all give slightly different values for the temperature of an O type star.

O stars are the hottest stars with surface temperatures of up to 50,000K or so, a far cry from 10 million K!

The spectral classification system is OBAFGKMLT (L and T are relatively recent additions). It represents a temperature scale with O being the hottest and T the coolest. If it seems like an odd order, I agree. The stellar classification system underwent many modifications as people dropped old classes and added new ones, leading to this odd collection.

A useful device for remembering OBAFGKM (L and T haven't been worked in yet /phpBB/images/smiles/icon_smile.gif Is "Oh be a fine girl(guy), kiss me".

My favorite is "Oilman Bush, Al “Florida” Gore? Kick Me!"

Rob

Wiley
2002-Mar-18, 04:44 PM
On 2002-03-18 09:50, Hale_Bopp wrote:

A useful device for remembering OBAFGKM (L and T haven't been worked in yet /phpBB/images/smiles/icon_smile.gif Is "Oh be a fine girl(guy), kiss me".



How 'bout amending: Lotsa Tongue. /phpBB/images/smiles/icon_smile.gif

Sorry, couldn't help myself.

Kaptain K
2002-Mar-18, 06:44 PM
The spectral classification system is OBAFGKMLT (L and T are relatively recent additions).
You forgot RNS (right now sweetie), the "carbon stars".

OBAFGKMRNSLT

Hale_Bopp
2002-Mar-18, 08:19 PM
I also left out W, the Wolf-Rayet stars. Guess we can add a Wow on the end /phpBB/images/smiles/icon_smile.gif

Rob