RA 52.7223° · Dec -8.8208° · star
9 more points to reach Common.
HD 21839 is a trash star. It lies about 797.4 light-years from Earth, sits in the constellation Eri, shines at apparent magnitude 9.74 and has spectral type F5.
Its spectrum reads F5 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Look for HD 21839 in the constellation Eri. At apparent magnitude 9.74, a small backyard telescope will bring it into view.
Like any astronomical target, HD 21839 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 21839 scores 6 points on Spacedle's rarity scale, which places it in the trash tier. Another 9 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and Yellow-white F-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.