RA 2.6967° · Dec 32.2426° · star
9 more points to reach Uncommon.
HD 640 is a common variable star. It lies about 2,609.2 light-years from Earth, sits in the constellation And, shines at apparent magnitude 7.55 and has spectral type M....
HD 640 is a common variable star worth 15 points across 2 science badges. Explore its facts, badges and place on the sky map, then add it to your dex on Spacedle.
Look for HD 640 in the constellation And. At apparent magnitude 7.55, it is an easy target for binoculars.
Like any astronomical target, HD 640 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 640 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 9 points would lift it into a rarer tier.
That score comes from 2 science badges — Variable star and Distant (>1000 ly) — 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.