RA 187.7523° · Dec 24.5672° · star
11 more points to reach Rare.
21 Com is an uncommon variable star. It lies about 269.8 light-years from Earth, sits in the constellation Com, shines at apparent magnitude 5.47 and has spectral type A2pvar.
Its spectrum reads A2pvar — 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 Com in the constellation Com. At apparent magnitude 5.47, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, 21 Com 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 Com scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.
That score comes from 5 science badges — Variable star, Naked-eye visible, White A-type star, Barely variable (under 0.05 mag) and A named variable 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.