RA 272.9483° · Dec -16.8939° · star
27 more points to reach Anomaly.
HD 166540 is an epic variable star. It lies about 1,792.1 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 8.14 and has spectral type B1Ib.
Its spectrum reads B1Ib — 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 HD 166540 in the constellation Sgr. At apparent magnitude 8.14, it is an easy target for binoculars.
Like any astronomical target, HD 166540 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 166540 scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 27 points would lift it into a rarer tier.
That score comes from 8 science badges — Variable star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Hot blue B-type star, Supergiant, Barely variable (under 0.05 mag) 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.