RA 279.1744° · Dec -17.2068° · star
6 more points to reach Rare.
HD 171640 is an uncommon star. It lies about 2,001 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 7.84 and has spectral type F0IV.
Its spectrum reads F0IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Look for HD 171640 in the constellation Sgr. At apparent magnitude 7.84, it is an easy target for binoculars.
Like any astronomical target, HD 171640 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 171640 scores 28 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 6 points would lift it into a rarer tier.
That score comes from 6 science badges — Star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Yellow-white F-type star and Subgiant (leaving the main sequence) — 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.