RA 6.0652° · Dec 52.0199° · star
6 more points to reach Epic.
HR 91 is a rare variable star. It lies about 1,000.5 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 5.58 and has spectral type B5IV.
Its spectrum reads B5IV — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
Look for HR 91 in the constellation Cas. At apparent magnitude 5.58, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, HR 91 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.
HR 91 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.
That score comes from 9 science badges — Variable star, Distant (over 1,000 light-years), Naked-eye visible, Never sets (northern circumpolar), Hot blue B-type star, Subgiant (leaving the main sequence), Blue-white star and Barely variable (under 0.05 mag) — 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.