RA 173.1065° · Dec 29.0454° · star
3 more points to reach Common.
HD 100255 is a trash star. It lies about 251.9 light-years from Earth, sits in the constellation UMa, shines at apparent magnitude 7.8 and has spectral type F5V.
Its spectrum reads F5V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Look for HD 100255 in the constellation UMa. At apparent magnitude 7.8, it is an easy target for binoculars.
Like any astronomical target, HD 100255 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 100255 scores 12 points on Spacedle's rarity scale, which places it in the trash tier. Another 3 points would lift it into a rarer tier.
That score comes from 4 science badges — Star, Never sets (northern circumpolar), Yellow-white F-type star and Main-sequence 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.