RA 272.4560° · Dec -27.1940° · star
9 more points to reach Rare.
HD 166021 is an uncommon star. It sits in the constellation Sgr, shines at apparent magnitude 10.22 and has spectral type A8/A9III:.
Its spectrum reads A8/A9III: — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
Look for HD 166021 in the constellation Sgr. At apparent magnitude 10.22, a small backyard telescope will bring it into view.
Like any astronomical target, HD 166021 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 166021 scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.
That score comes from 5 science badges — Star, Toward the galactic centre, On the zodiac, White A-type star and Giant 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.