RA 89.4986° · Dec 25.9539° · star
3 more points to reach Uncommon.
139 Tau is a common star. It lies about 1,553.1 light-years from Earth, sits in the constellation Tau, shines at apparent magnitude 4.81 and has spectral type B1Ib.
139 Tau is a common star worth 21 points across 3 science badges. Explore its facts, badges and place on the sky map, then add it to your dex on Spacedle.
Look for 139 Tau in the constellation Tau. At apparent magnitude 4.81, it can be glimpsed with the unaided eye under dark skies.
Like any astronomical target, 139 Tau 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.
139 Tau scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Distant (>1000 ly) and Naked-eye visible — 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.