RA 234.2299° · Dec 32.5817° · star
5 more points to reach Rare.
HD 139421 is an uncommon variable star. It lies about 1,140.4 light-years from Earth, sits in the constellation CrB, shines at apparent magnitude 9.14 and has spectral type M6.
Its spectrum reads M6 — 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 139421 in the constellation CrB. At apparent magnitude 9.14, a small backyard telescope will bring it into view.
Like any astronomical target, HD 139421 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 139421 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 6 science badges — Variable star, Distant (over 1,000 light-years), Cool red M-type star, Red dwarf, 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.