Remembering star colour order

[25585]

Is helped by this mnemonic. 

"Wow Oh Be A Fine Girl Kiss Me Right Now Cutie"

WO - Wolf Rayet - very hot very blue stars (50000+K)

O -  very Blue (30000 to 50000K) e.g. Alnitak

B - Blue e.g. Rigel, Spica

A - White e.g. Altair, Sirius, Vega, Deneb

F - Yellow-white e.g. Procyon, Polaris

G - Yellow e.g. Sun, Capella

K - Orange e.g. Aldebaran, Pollux

M - Red e.g. Betelgeuse, Antares, Mira

R, N, C - deep Red carbon stars

There are grades in-between e.g G2

[michael.h.f.wilkinson]

Cutie is sometimes replaced by Sweetie for S-type stars

[ronin]

Not sure R, N, C are deep red carbon stars. The catagory I thought dropped down into red dwarfs and smaller stars that can get down to Big Jupiter size, however I did hear of someone referring to Saturn size "stars". Will say that people seem to be trying to "discover" smaller and smaller "stars". Not sure some support fusion which I also thought was a requirement for a "star".

At the end where you have R, N, C, I have read L, T, Y instead, may be a US catagorising. I have a suspicion there are 2 or 3 catagory options being used/proposed and differnt people are using the one they are a champion of. So be prepared to read or hear of alternatives.

Then eventually the IAU will come up with a different one that is a sort of inclusion of the main ones or an exclusion of the main ones. That way they either keep everyone a bit happy or upset everyone equally.

[25585]

I think brown dwarves are the borderline between sub-stellar mass gas giants & stars. Too hot to be planets, not hot enough to be red. 

My reference literature is 80s/90s so I expect there has been re-categorising, as for what makes a planet classification (poor Pluto  )