RA 234.1174° · Dec 15.1014° · star
5 more points to reach Rare.
HD 139216 is an uncommon variable star. It lies about 671.1 light-years from Earth, sits in the constellation Ser, shines at apparent magnitude 6.51 and has spectral type M5II-III.
Its spectrum reads M5II-III — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
Look for HD 139216 in the constellation Ser. At apparent magnitude 6.51, it is an easy target for binoculars.
Like any astronomical target, HD 139216 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 139216 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.
That score comes from 5 science badges — Variable star, Cool red M-type star, Bright giant, Gently variable 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.