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Stellar_Classes.t
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# Classes of stars, from http://crash.ihug.co.nz/~r-smith/worlds/part2.html
# super giant (0.0001 chance)
0.00001 cB
0.00001 cA
0.00002 cF
0.00002 cG
0.00002 cK
0.00002 cM
# giant (0.0099 chance)
0.0004 gF
0.0005 gG
0.0045 gK
0.0045 gM
# main sequence stars (0.92 chance)
0.0001 O generally high (5-9) subclass
0.0099 B
0.02 A
0.04 F
0.08 G
0.15 K
0.63 M
# white dwarfs (0.07 chance)
0.01 DB
0.02 DA
0.02 DF
0.01 DG
0.0095 DK
0.00045 NS - Neutron star
0.00005 BH - Black hole
what about quasars?
# Stellar density
one star system per 600 cubic light-years of space
# Multiple star systems
His odds:
0.40 1 star
0.40 2 stars
0.09 3 stars
0.01 more stars
Its close, but completely non-scientific.
# Planetary existence odds
Poor. Very poor.
# Stellar mass criteria:
0.08 S is minimum mass required for the star to ignite and burn.
A star of that mass would be an M9 for sure, and would burn for
friggin eternity. That's 26622 earth masses.
The star systems in Carl Sagan's Cosmos include one which has a
planet 31164 Earth masses, and the system is binary (planet ignited)
Is this possible in this version of ACCRETE?
Stars with stellar masses of 0.08 to 6 S will likely become white
dwarfs when they die, but suns over that mass will likely nova.
Jupiter is, like 318 times Earth's mass. The largest planet I have
seen accrete2 create is 2340 Earth masses.
Look at http://seds.lpl.arizona.edu/nineplanets/nineplanets/
for info on distance, radius, and masses of all of the planets and
all of the planets' moons.
# Age on main sequence (Tau)
Based on (mass of star) / (mass of sol) = M_ratio (mass ratio)
time_sol * M_ratio ^ x
if M_ratio < 0.7, then x = -3.75
M_ratio >= 0.7, then x = -1.125 - 3.75*M_ratio
# Radius (R)
R_star = R_sol * L_ratio ^ 0.233
where L_ratio = L_star / L_sol
# Luminosity (L)
L_star = L_sol * 10 ^ (0.4 * (Mv_sol - Mv_star))
# Surface temp (T)
T = L / (4 * pi * sigma * R^2)
# Ecosphere range
from 0.53 to 1.02 times the luminosity at Earth's orbit, i.e.
X_earth * sqrt ( L / (1.02*L_sol) ) < X < X_earth * sqrt ( L / (0.53*L_sol) )
# Luminosity vaires thru a star's lifetime as
L_zero_age_main_sequence * e ^ ( 0.045 * (tau/tau_ms)^1.33 )
# Eccentricity and axial tilt
Does accrete2 do this? Oh, yes it does!
# Planets:
maximum mass, in earth masses:
(gamma_E / (G*gamma_rho))^1.5 * Z^3 / r^2
where gamma_E = e^2 / (4*pi*epsilon_0*m_p^1.333)
gamma_rho = 1.0 - IF
IF = inertia factor = 2/3 - 4/15 * sqrt( 10*pi^2*r*3/T^2/G/m/epsilon - 1 )
shortest possible period (hours), otherwise planet breaks up
P = sqrt ( 2*pi / (0.19*G*rho) ) rho = density
plate tectonics ending time (billions of years)
pte = (m/m_someplace)^0.71
maximum mountain height h_max
h_max = h_max_someplanet / density
Roche limit (if moon gets any closer, it breaks up)
R_l_in_km = 0.00244 * r * cube_root( rho_planet / rho_moon )