RA 246.0451° · Dec 6.9482° · star
6 more points to reach Uncommon.
21 Her is a common star. It lies about 366.5 light-years from Earth, sits in the constellation Her, shines at apparent magnitude 5.83 and has spectral type A2sp....
Its spectrum reads A2sp... — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
Look for 21 Her in the constellation Her. At apparent magnitude 5.83, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, 21 Her 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.
21 Her scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Naked-eye visible 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.