RA 281.8945° · Dec -6.3075° · star
5 more points to reach Rare.
HD 173820 is an uncommon star. It sits in the constellation Sct, shines at apparent magnitude 9.92 and has spectral type O8.
Its spectrum reads O8 — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.
Look for HD 173820 in the constellation Sct. At apparent magnitude 9.92, a small backyard telescope will bring it into view.
Like any astronomical target, HD 173820 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 173820 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and Blazing O-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.