RA 53.6606° · Dec 63.8889° · star
7 more points to reach Uncommon.
HD 21806 is a common star. It sits in the constellation Cam, shines at apparent magnitude 7.77 and has spectral type B1Vn....
Its spectrum reads B1Vn... — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
Look for HD 21806 in the constellation Cam. At apparent magnitude 7.77, it is an easy target for binoculars.
Like any astronomical target, HD 21806 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.
HD 21806 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.
That score comes from 4 science badges — Star, Never sets (northern circumpolar), Hot blue B-type star and Main-sequence 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.