RA 113.6524° · Dec 31.8905° · star
1 more point to reach Rare.
Castor B is an uncommon star. It lies about 51.5 light-years from Earth, sits in the constellation Gem, shines at apparent magnitude 2.85 and has spectral type A m.
It is a binary: two stars orbiting a shared centre of mass. More than half of all the 'stars' you can see are actually multiple systems.
Look for Castor B in the constellation Gem. At apparent magnitude 2.85, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, Castor B is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.
Castor B scores 33 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.
That score comes from 6 science badges — Star, Naked-eye visible, Binary star, Has a proper name, On the zodiac and White A-type star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.