|
Star Tables
These star tables
and some of the comments were sent to us by Gerald Nordley,
science
fiction writer, member of the CONTACT group, and a very good
friend to world builders! Thank you very much for your help,
Mr Nordley!
A simplified set of star tables may be found
here.
Notes on these star tables:
The stars in these tables are arranged in
the classes used in the Main Sequence.
Choose your star from these tables and you will have some of
the numbers that you need for your solar system and your planet.
Our sun is a G2 star. As we found out from
our hands-on activity, our sun formed
4.5 billion years ago. Earth also formed about 4.5 billion years
ago, and 3.2 billion years ago, or perhaps even earlier, the
first single celled life forms appeared. When you consider that
the earth had to cool from a molten state first, life seems to
have appeared quite quickly. However, the jump to multicellular
life forms took a long time. Multicellular life forms began
to develop only 600 million years. If you want to have live forms
that you can actually see, you need to choose a star with a long
enough life time.
You should choose your star type from these
tables. Write down the information about that star's row, with
the headings.
What the Headings mean:
Class:
See the page on Main Sequence
Temperature in Degrees Kelvin:
See page on Temperatures
in Space. The temperature given is the surface temperature
of the star.
Bolometric Absolute Magnitude:
Stellar magnitude over all wavelengths as
seen from ten Parsecs 32.6 Light years). At that distance,
the sun would appear to be a 4th magnitude star (4.75 to be precise).
Stars are different sizes, and some are much
brighter than others. Astronomers classify stars by brightness.
This is difficult because some stars are relatively close to
us, while others are very far away. This measurement tells us
how bright the different stars are when viewed from the same
distance (but not the same place).
Bolometric Luminosity: a star's power output over all wavelengths
(Sol = 1)
This includes light, heat,
ultraviolet radiation, infrared radiation, gamma rays, and so
on. Many wavelengths of the energy that stars radiate cannot
be detected by our senses, but only with special instruments.
Bolometric Luminosity is the
total energy put out by a star spread over all wavelengths. Use
it for calculating the total energy balance and average effective
temperature for a planet.
This is probably best for
photosynthesis as well, however, for planets with deep atmospheres
around very red stars, one might want to research atmospheric
absorption as a function of wavelength and see how that compares
to the stars blackbody spectrum. For planets with thick atmospheres
or enhanced ozone layers around stars hotter than the sun, use
visual luminosity for photosynthesis, as atmospheres attenuate
ultraviolet light much more than visual.
L
Zams:
Zero Age luminosity; bolometric luminosity
after the star's
initial contraction; this is problematical for late M stars
and below, which contract essentially forever.
Visual Luminosity:
in terms of Sol at the same distance. For
hotter or cooler stars this is less than L bol, because much
of those star's radiation is in the invisible ultraviolet (very
hot) or infrared (warm) part of the spectrum. If one was close
enough to a red dwarf that it appeared as bright as the sun,
one would get about 100 times less ultraviolet intensity.
Mass (Mass of our sun = 1): See page on Weight,
Mass, and Density.
Radius:
Radii are estimated from temperature and luminosity,
except for the planets at the bottom. The radius is the distance
from the center of the star to its outer boundary.
Terrestrial Equivalent Orbit in
AUs:
the distance to a star where one gets Earth's
solar intensity (1372 W/m^2). For very dim stars,tidal effects
are of concern.
This is important because it will help you
to put your world in the Life Zone
of your solar system.
Lifetime in Billions of Years:
This is how long your star will burn in a
stable way. Remember, you need to allow time for your life forms
to develop.
Important Math Note:
In numbers in the form of 1.23E-3,
the E-3 stands for ten to the inverse third power, and
is an instruction to divide by ten cubed (1000). (10 cubed means
10 x 10 x 10)
Thus E-3 means thousandths (1/1000)
E-6 means millionths (1/1,000,000) and
E-9 means (U.S.) billionths (1/1,000,000,000).
If you look at these tables you will see interesting
changes as the stars get smaller. Pay special attention to the
colored sections of the tables, as you will be using these numbers
in planning your own solar system.
|
O Class Stars -- Very Large, Very Hot, Very Fast
Burning |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass
(Mass of our sun = 1) |
Radius |
Terrestrial Equivalent Orbit
in AUs |
Lifetime
in billions of years |
| |
|
|
|
|
|
|
|
|
|
| 04 |
48000 |
-10.24 |
990000.00 |
980000.00 |
1.75E4 |
90.000 |
14.400 |
995.00 |
.002 |
| 05 |
44500 |
-9.99 |
790000.00 |
560000.00 |
1.46E4 |
60.000 |
15.000 |
889.00 |
.004 |
| 06 |
41000 |
-9.31 |
420000.00 |
238000.00 |
1.20E4 |
37.000 |
12.900 |
648.00 |
.005 |
| 07 |
38000 |
-8.79 |
260000.00 |
140000.00 |
9350.00 |
30.000 |
11.800 |
510.00 |
.006 |
| 08 |
35800 |
-8.33 |
170000.00 |
84500.00 |
6960.00 |
23.000 |
10.800 |
412.00 |
.008 |
| 09 |
33000 |
-7.72 |
97000.00 |
62700.00 |
4820.00 |
23.300 |
9.560 |
311.00 |
.009 |
|
B Class Stars -- Hot and Fast Burning |
| Class |
Temp/K |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial
Equivalent Orbit
in AUs |
Lifetime in billions
of years |
| |
|
|
|
|
|
|
|
|
|
| B0 |
30000 |
-7.04 |
52000.00 |
40800.00 |
3020.00 |
17.500 |
8.470 |
228.00 |
.010 |
| B1 |
25400 |
-5.76 |
16000.00 |
18800.00 |
1420.00 |
14.200 |
6.560 |
126.00 |
.013 |
| B2 |
22000 |
-4.64 |
5700.00 |
9720.00 |
698.00 |
10.900 |
5.220 |
75.50 |
.020 |
| B3 |
18700 |
-3.45 |
1900.00 |
3150.00 |
339.00 |
7.600 |
4.170 |
43.60 |
.043 |
| B5 |
15400 |
-2.55 |
830.00 |
1500.00 |
231.00 |
5.900 |
4.060 |
28.80 |
.066 |
| B6 |
14000 |
-2.00 |
500.00 |
823.00 |
175.00 |
5.200 |
3.810 |
22.40 |
.075 |
| B7 |
13000 |
-1.51 |
320.00 |
496.00 |
133.00 |
4.500 |
3.540 |
17.90 |
.198 |
| B8 |
11900 |
-.89 |
180.00 |
308.00 |
91.90 |
3.800 |
3.170 |
13.40 |
.367 |
| B9 |
10500 |
-.19 |
95.00 |
187.00 |
63.30 |
3.350 |
2.960 |
9.75 |
.475 |
|
A Class Stars -- Do Not Last Long Enough to Support
Complex Life Forms |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
Lifetime in billions
of years |
| |
|
|
|
|
|
|
|
|
|
| A0 |
9520 |
.42 |
54.00 |
87.20 |
43.70 |
2.900 |
2.710 |
7.35 |
.583 |
| A1 |
9230 |
.89 |
35.00 |
76.60 |
30.20 |
2.720 |
2.320 |
5.92 |
.627 |
| A2 |
8970 |
1.21 |
26.00 |
66.10 |
23.10 |
2.540 |
2.120 |
5.10 |
.670 |
| A3 |
8720 |
1.44 |
21.00 |
55.60 |
19.20 |
2.360 |
2.010 |
4.58 |
.713 |
| A5 |
8200 |
1.88 |
14.00 |
34.60 |
13.00 |
2.000 |
1.860 |
3.74 |
.800 |
| A7 |
7850 |
2.20 |
10.50 |
25.30 |
10.00 |
1.840 |
1.760 |
3.24 |
1.120 |
| A8 |
7580 |
2.41 |
8.60 |
20.60 |
8.37 |
1.760 |
1.710 |
2.93 |
1.280 |
|
Class F Stars: Some of These Might Have Life-Bearing
Planets |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
Lifetime in billions
of years |
| |
|
|
|
|
|
|
|
|
|
| F0 |
7200 |
2.72 |
6.50 |
11.20 |
6.38 |
1.600 |
1.640 |
2.55 |
1.600 |
| F2 |
6890 |
3.17 |
4.30 |
6.57 |
4.14 |
1.520 |
1.460 |
2.07 |
1.760 |
| F5 |
6440 |
3.49 |
3.20 |
4.47 |
3.00 |
1.400 |
1.440 |
1.79 |
3.440 |
| F8 |
6200 |
3.94 |
2.10 |
2.51 |
1.93 |
1.190 |
1.260 |
1.45 |
6.880 |
|
G Class Stars: Possible Suns for Planets with Life:
The Sun is a G2 Star |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
Lifetime
in billions of years |
| |
|
|
|
|
|
|
|
|
|
| G0 |
6030 |
4.31 |
1.50 |
1.21 |
1.36 |
1.050 |
1.130 |
1.22 |
9.180 |
| G2 |
5860 |
4.65 |
1.10 |
.74 |
.97 |
.998 |
1.020 |
1.05 |
10.100 |
| G5 |
5770 |
5.01 |
.79 |
.63 |
.69 |
.920 |
.893 |
.89 |
14.000 |
| G8 |
5570 |
5.20 |
.66 |
.51 |
.56 |
.842 |
.875 |
.81 |
17.900 |
|
K Class Stars: Small, Dim, Red Stars: Could Perhaps
Support Life On Inner Planets |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
Lifetime in billions
of years |
| |
|
|
|
|
|
|
|
|
|
| K0 |
5250 |
5.69 |
.42 |
.45 |
.34 |
.790 |
.786 |
.65 |
21.100 |
| K1 |
5080 |
5.83 |
.37 |
.41 |
.28 |
.766 |
.788 |
.61 |
long |
| K2 |
4900 |
6,09 |
.29 |
.38 |
.21 |
.742 |
.750 |
.54 |
|
| K3 |
4730 |
6.21 |
.26 |
.34 |
.18 |
.718 |
.762 |
.51 |
|
| K4 |
4590 |
6.55 |
.19 |
.31 |
.12 |
.694 |
.692 |
.43 |
very |
| K5 |
4350 |
6.81 |
.15 |
.27 |
82.4E-3 |
.670 |
.684 |
.39 |
long |
| K7 |
4060 |
7.25 |
.10 |
.19 |
42.1E-3 |
.606 |
.641 |
.32 |
|
|
M Class Stars: Less than Half the Mass of Our Sun |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass
of our sun = 1) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
| |
|
|
|
|
|
|
|
|
| M0 |
3850 |
7.53 |
77.00E-3 |
52.00E-3 |
23.0E-3 |
.510 |
.626 |
.28 |
| M1 |
3720 |
7.79 |
61.00E-3 |
38.80E-3 |
14.6E-3 |
.445 |
.597 |
.25 |
| M2 |
3580 |
8.12 |
45.00E-3 |
27.70E-3 |
8.42E-3 |
.400 |
.553 |
.21 |
| M3 |
3470 |
8.36 |
36.00E-3 |
24.00E-3 |
5.30E-3 |
.350 |
.527 |
.19 |
| M4 |
3370 |
9.05 |
19.00E-3 |
19.40E-3 |
2.26E-3 |
.300 |
.406 |
.13 |
| M5 |
3240 |
9.65 |
11.00E-3 |
14.70E-3 |
.95E-3 |
.250 |
.334 |
.11 |
| M6 |
3050 |
10.44 |
5.30E-3 |
10.70E-3 |
.29E-3 |
.207 |
.262 |
72.8E-3 |
| M7 |
2940 |
10.92 |
3.40E-3 |
7.06E-3 |
.15E-3 |
.163 |
.226 |
58.3E-3 |
| M8 |
2640 |
12.05 |
1.20E-3 |
2.67E-3 |
29.30E-6 |
.120 |
.166 |
35.0E-3 |
| M9 |
2510 |
13.56 |
0.30E-3 |
.30E-3 |
1.16E-6 |
.100 |
.092 |
17.0E-3 |
Below: The
E0 Class contains the the lowest mass Main Sequence
stars.
Stars less massive than class E0 are called Brown Dwarfs.
|
Small, Heat-Radiating Bodies Less Than a Tenth
the Mass of Our Sun |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Mass of our sun
= 1) |
Radius |
Terrestrial Equivalent Orbit
in AUs |
| |
|
|
|
|
|
|
|
|
| E0 |
1800 |
15.74 |
40.00E-6 |
NA |
277.0E-9 |
.080 |
.065 |
6.3E-3 |
| E2 |
1600 |
16.06 |
30.00E-6 |
NA |
4.2E-9 |
.072 |
.072 |
5.5E-3 |
| E4 |
1300 |
16.74 |
16.O0E-6 |
NA |
1.0E-9 |
.064 |
.079 |
4.0E-3 |
| E6 |
1000 |
17.25 |
10.00E-6 |
NA |
-- |
.053 |
.106 |
3.7E-3 |
| E8 |
800 |
18.00 |
5.00E-6 |
NA |
Too |
.040 |
.117 |
2.2E-3 |
Below:
MJ means Jupiter masses, each about 1/1000 the mass of the sun.
The Brown Dwarf/Jovian Transition is between E8 and J0
|
Astronomical Bodies Smaller than Mass of Jupiter:
Radiate Heat |
| Class |
Temperature in degrees Kelvin |
Bolometric Absolute Magnitude |
Bolometric Luminosity |
L Zams |
Visual Luminosity |
Mass (Compared
to mass of Jupiter (.001 of our sun)) |
Radius |
Terrestrial Equivalent
Orbit
in AUs |
| |
|
|
|
|
|
|
|
|
| J0 |
700 |
18.56 |
3.00E-6 |
NA |
dim |
MJ .118 |
.118 |
1.7E-3 |
| J2 |
600 |
19.31 |
1.50E-6 |
NA |
to |
MJ .114 |
.114 |
1.2E-3 |
| J4 |
400 |
21.06 |
.30E-6 |
NA |
see |
MJ .114 |
.114 |
.5E-3 |
| J7 |
100 |
27.25 |
1.00E-9 |
NA |
with |
MJ .106 |
.106 |
Below |
| J8 |
80 |
29.11 |
.18E-9 |
NA |
human |
MJ .070 |
.070 |
surface |
| J9 |
50 |
32.56 |
7.50E-12 |
NA |
eyes |
MJ .037 |
.037 |
Below |
Non-
Luminous |
30 |
34.75 |
1.00E-12 |
NA |
-- |
MJ .037 |
.037 |
surface |
The bottom end of the Jovian scale consists of Jupiter,
Saturn
Neptune and Uranus in that order, with effective temperatures
from Lang, adjusted for solar heating and known radius values
Jupiter is a J7.
|