Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 07-21-2019, 08:18 PM   #1
manhamster
 
Join Date: Jul 2019
Default [ SPACE 4e ] Minimum Luminosity

I have not turned up entries concerning this.

Concerns the minimum luminosity table ( correction the L-Min on the Stellar Evolution Table ). Does anyone know the possible formula for behind those L-Min numbers? Probably not the actual scientific formula unless you think that was the one used.

I tried some variations, going with the assumption that it is calculated based on stellar mass ( in Sols ), but with no luck.

I am inquiring partly of out curiosity and the other part is using a formula ( in a project I am toying with ) would be more efficient than doing a bunch of IF statements ( what I'm using is not Excel so I do not have the benefit of using VLOOkUP ).

Last edited by manhamster; 07-22-2019 at 10:07 AM.
manhamster is offline   Reply With Quote
Old 07-21-2019, 09:34 PM   #2
Captain Joy
 
Captain Joy's Avatar
 
Join Date: Nov 2006
Location: Heartland, U.S.A.
Default Re: [ SPACE 4e ] Minimum Luminosity

Could you clarify a bit? You’re asking for a “formula” for luminosity as a function of mass for low-mass stars?
Captain Joy is offline   Reply With Quote
Old 07-21-2019, 09:49 PM   #3
Sunrunners_Fire
 
Join Date: Mar 2010
Location: Bullhead City, AZ
Default Re: [ SPACE 4e ] Minimum Luminosity

Quote:
Originally Posted by manhamster View Post
I have not turned up entries concerning this.

Concerns the minimum luminosity table. Does anyone know the possible formula for minimum luminosity?

I tried some variations, going with the assumption that it is calculated based on stellar mass ( in Sols ), but with no luck.

I am inquiring partly of out curiosity and the other part is using a formula ( in a project I am toying with ) would be more efficient than doing a bunch of IF statements ( what I'm using is not Excel so I do not have the benefit of using VLOOkUP ).
"minimum luminosity" for ...? Minimum to do what?

Absent clarification, more information can be found here.
__________________
"Art thou wroth? Wherefore art thou wroth, brother?"
Sunrunners_Fire is offline   Reply With Quote
Old 07-21-2019, 09:50 PM   #4
Agemegos
 
Agemegos's Avatar
 
Join Date: May 2005
Location: Oz
Default Re: [ SPACE 4e ] Minimum Luminosity

Quote:
Originally Posted by Captain Joy View Post
Could you clarify a bit? You’re asking for a “formula” for luminosity as a function of mass for low-mass stars?
I think the OP wants a formula for the luminosity of a star at the beginning of its life on the main sequence, as a function of mass. That's the value given as "L-Min" on the Stellar Evolution Table, p. 103 of GURPS Space.

In real astrophysics that is called the "zero-age main sequence luminosity". There's a fitted analytical function on the second page of Tout, C. A., Pols, O. R., Eggleton, P. P., & Han, Z. "Zero-age main-seqence radii and luminosities as analytic functions of mass and metallicity" Monthly Notices of the Royal Astronomical Society, Volume 281, Issue 1, pp. 257-262, but I don't think you're going to like it.
__________________
© copyright Brett Evill
FLAT BLACK discussion group at tekeli.li
On-line texts at flatblack.wikidot.com

Last edited by Agemegos; 07-21-2019 at 10:18 PM.
Agemegos is offline   Reply With Quote
Old 07-22-2019, 12:54 AM   #5
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: [ SPACE 4e ] Minimum Luminosity

In practice, starting with a table of values and extrapolating will get you closer than you can possibly need for gaming.
__________________
My GURPS site and Blog.
Anthony is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 02:17 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.