RA 330.9661° · Dec 44.5903° · star
1 more point to reach Common.
HD 209640 is a trash star. It lies about 1,342.2 light-years from Earth, sits in the constellation Lac, shines at apparent magnitude 7.78 and has spectral type A0.
Its spectrum reads A0 — 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 209640 in the constellation Lac. At apparent magnitude 7.78, it is an easy target for binoculars.
Like any astronomical target, HD 209640 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 209640 scores 14 points on Spacedle's rarity scale, which places it in the trash tier. Another 1 point would lift it into a rarer tier.
That score comes from 3 science badges — Star, Distant (over 1,000 light-years) and White A-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.