User Guide

A NEW SUN
APPENDIX 5
217
Planet’s days are only about 18 hours, so sleep cycles must be corresponding-
ly reduced. Its years are slightly longer than Earth’s years., but not enough to
make a noticeable difference. The greater difference is Planet’s lack of seasons.
With only a slight axial tilt, any seasonal differences are minimal.
Neither of Planet’s moons exert as much tidal pull as Earth’s moon, but when
they combine, tides will run slightly higher than on Earth.
Once every 80 years, as Alpha Centauri B reaches perihelion (its closest
approach to Alpha Centauri A), it generates enough heat to increase Planet’s
average temperature by 0.3° C. That doesn’t seem like much, but Planet’s cli-
mactic system might easily amplify this to uncomfortable levels. In fact, any
life native to Planet may have evolved cyclic responses to this event.
Planetary constants Earth Planet (Chiron) P/E Ratio
Mass (kg) 5.98 x 10
24
1.10 x 10
25
1.84
Equat. radius (km) 6380 7540 1.18
Dist. from star (km) 1.50 x 10
8
1.60 x 10
8
1.07
Axial tilt (degrees) 23.45 2.00 0.09
Surface area (km
2
) 5.10 x 10
8
7.18 x 10
8
1.41
Standard gravity (m/s
2
) 9.81 12.85 1.31
Escape velocity (m/s) 11,184 13,947 1.25
Density (kg/m
3
) 5519 6150 1.11
Size of sun (degrees) 0.27 0.27 1.02
Year (Earth days) 365 389 1.06
Year (Planet days) 500 532 1.06
Day (hours) 24.00 17.53 0.73
Mountain height (m) 10,626 8112 0.76
Horizon distance (m) 5051 5493 1.09
Ocean tide (sun) (m) 0.12 0.12 0.94
Ocean tide (Nessus) (m) 0.27 0.18 0.67
Ocean tide (Pholus) (m) 0.11
Ocean tide (all) (m) 0.39 0.41 1.05