RA 173.9463° · Dec -61.5605° · star
8 more points to reach Rare.
HD 100840 is an uncommon star. It sits in the constellation Cen, shines at apparent magnitude 8.16 and has spectral type M0Iab.
Its spectrum reads M0Iab — 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 100840 in the constellation Cen. At apparent magnitude 8.16, it is an easy target for binoculars.
Like any astronomical target, HD 100840 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 100840 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Cool red M-type star and Supergiant — 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.