Space Opera's discretionary design of planets left me wanting more information about reasonable values for things like ecosphere and, therefore, oribtal distance and so on. I went looking and found some information in a book on astronomy which I condensed down into this table:
|
|
Max |
|
Min |
|||
B0 |
23,000 |
1072 |
979 |
876 |
|||
B5 |
15,000 |
866 |
790 |
707 |
|||
A0 |
11,000 |
742 |
677 |
606 |
|||
A5 |
8,600 |
655 |
599 |
535 |
|||
F0 |
7,400 |
608 |
555 |
497 |
|||
F5 |
6,500 |
570 |
520 |
465 |
|||
giant
G0 |
5,600 |
529 |
483 |
432 |
|||
giant
G5 |
4,700 |
484 |
443 |
396 |
|||
giant
K5 |
4,200 |
458 |
418 |
374 |
|||
giant
M2 |
3,400 |
412 |
376 |
337 |
|||
giant
M5 |
3,100 |
394 |
359 |
321 |
|||
N |
2,700 |
360 |
329 |
294 |
|||
Me(max). |
2,600 |
339 |
310 |
277 |
|||
Me(min). |
2,300 |
287 |
262 |
235 |
|||
dwarf G0 |
6,000 |
548 |
500 |
447 |
|||
dwarf G5 |
5,600 |
529 |
483 |
432 |
|||
dwarf K9 |
5,100 |
505 |
461 |
412 |
|||
dwarf K5 |
4,400 |
469 |
428 |
383 |
|||
dwarf M |
3,400 |
412 |
376 |
337 |
The Math Used:
I did this chart many years ago, when I was in high school, so I make no claims as to the realism of the methods used. However, at least
they do give consistent results, so for a game they may well be good enough.
Anyway, assume that Earth is at the optimum stellar distance around a dG0 star. Therefore, the Optimum
Stellar Ecosphere (OSE) can be calculated as follows:
OSE=6000K/(500LS)Ù2, this is simply a coefficient and is
based on the idea that the temperature of the star is proportional to the radiation emitted and falls off as the square of the
distance. Your mileage may vary.
If we solve the equation, we find the OSE coefficient is .024K/LSÙ2
Thus the actual Optimum Stellar Ecosphere distance in LS is the square root of the Temperature of the star divided by the coefficient:
Ö(T/0.024)
Somehow, I decided to calculate the maximum and minimum SE coefficients by using the temperatures of dK0 and F0 stars This gives results
of .020 and .030, which can be plugged into the above formula to determine the maximum and minimum
ecospheres.
Example:
For a type M dwarf star, with a temperature of 3,400K,
OSE = Ö(3400/.024) =
Ö(141,666.67)=376
MxSE = Ö(3400/.020) =
Ö(170,000) = 412
MnSE = Ö(3400/.030) =
Ö(113,333.33) = 337