Stellar Type

[spidersrepublic]

How do you decipher the "Stellar Type"? Used in system UWPs

eg:
K1 II M1 V

I know the M1 means 1 Stellar Mass. What's 1 stellar mass relative to our sun?

 

[Old timer]

Actually, that looks like a binary star system from a UWP, if it is then the first one is a K1 type star, and the second is a M1 type star. The second number are Roman numerals and indicate stellar illumination (i think). Earth sun,if i remember correctly would be G5 V in traveller UWP terms.

 

[rust]

Your example is actually a binary system consisting of
a K1 II star and a M1 V star.
"K1" and "M1" are the spectral types of the two stars,
based on their surface temperatures, while "II" and "V"
are their current stages of stellar evolution, with "II"
being a giant and "V" a main sequence dwarf.

 

[spidersrepublic]

thanks for the fast replies

so the first letter is the star type and the second is the stars life cycle.

Where would i find the tables that show all this stuff?

 

[rust]

You could start here:

http://en.wikipedia.org/wiki/Stellar_classification

 

[F33D]

thanks for the fast replies

so the first letter is the star type and the second is the stars life cycle.

Where would i find the tables that show all this stuff?

A little mnemonic to remember types from hottest to coldest: Oh Be A Fine Girl Kiss Me

 

[Rikki Tikki Traveller]

M = Red Star (Very common, very dim)
K = Orange Star (Common, dimmer than our Sun)
G = Yellow Star (Less Common, like our Sun)
F = White Star (Uncommon, brighter and younger than the Sun)
A = White Star (Very Uncommon, Very Bright - like Sirius)
B = Blue-White Star (Extremely uncommon, extremely bright, very young)
O = Blue Star (Incredibly uncommon, incredibly bright, extremely young)

Habitable planets can only evolve around M, K, G and some F stars, the others evolve into Red Giants before life can develop on any planets that form. A, B and O stars don't even have enough time for the planets to cool down enough to have solid surfaces before they evolve.

The numbers are fine gradation between the colors with the smaller number being brighter than the larger number.

The roman numeral are the size:

VII (or D) = Dwarf (as in white dwarf)
VI - Pre-Main Sequence, very small
V - Main Sequence (something like 80% of all stars are this size)
IV - Post main sequence, usually evolving off to become a red giant
III - Red Giant (although some are other colors, this is the common term for them)
II - Large giant (Very rare and a 'special case')
I - Super-Giants - these are the biggest and brightest stars out there - incredibly rare and very short lived.

BTW - Most of the stars listed in the OTU tables are HORRIBLY wrong. You won't get habitable planets orbiting white dwarfs etc. but Traveller doesn't seem to care.