RA 51.6687° · Dec 72.2060° · star
5 more points to reach Common.
HD 20831 is a trash star. It lies about 518.5 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 7.13 and has spectral type F0.
Its spectrum reads F0 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Look for HD 20831 in the constellation Cas. At apparent magnitude 7.13, it is an easy target for binoculars.
Like any astronomical target, HD 20831 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 20831 scores 10 points on Spacedle's rarity scale, which places it in the trash tier. Another 5 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Never sets (northern circumpolar) and Yellow-white F-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.