61 Ursae Majoris

61 Ursae Majoris System
Position: Primary (A)
Spectral Class: G8 V
Color: Yellow
Type: Main Sequence Star
Coordinates: -24.4X, 2.2Y, 16.7Z
Mass: 0.87.Sol
Absolute Bolometric Magnitude: 5.55
Effective Surface Temperature: 5140°K
Luminosity: 0.52.Sol
Radius: 0.91.Sol
Life Zone: 0.59 au – 0.86 au
Optimum Distance: 0.72 au

The Star

Located 29.65 light years from Earth in the fertile Ursae Majoris Corridor of the French Arm, 61 Ursae Majoris is a yellow dwarf star whose third planet supports the second largest number of colonies on a single planet in the human sphere. The system was first surveyed by the ESAS Argonaute in the year 2226 A.D. Fourteen planets were discovered, although few of these were of anything more than abstract scientific interest. The star, like most of its kind, has an extensive planetary system. One of these worlds, Joi, is located inside the habitable zone.

The Planets

The planetary system includes 14 worlds, although most of these are small, relatively unimportant ice balls offering nothing in the way of worthwhile features. All of them were named by Captaine DeSalles of the Argonaute in his native French.

Planet I, a hothouse world designated Chaud, is a large-diameter planet with a dense atmosphere. Gris, planet II, is smaller but similar in nature to Chaud. Both resemble Sol’s Venus, shrouded in impenetrable clouds which cause a run-away greenhouse effect and temperatures hundreds of degrees beyond what humans find tolerable.

The third planet was named Joi, and it is the colonized planet of the system.

The outer worlds are mostly of little importance. Planets IV and V (Frais and Froid) are both failed core planets, would-be gas giants which lacked sufficient mass to realize their potential. The next seven planets in the system are all either ice balls or even smaller failed core worlds. Planet XIII, Hiver, circles the star at an orbital radius of over 73 AU; it is a Mars-type desert world with a thin atmosphere but with some potential for resource extraction. The outermost world, 61 Ursae Majoris XIV, is a spectacular gas giant named Grandpere which has an orbital radius of over 154 AU, completing one circuit of the star every four and a quarter million years. The entire planetary system is considered to be made up of worlds classed as Population II.

61 Ursae Majoris

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