About HD 166263
HD 166263 is a rare star. It sits in the constellation Sgr, shines at apparent magnitude 7.78 and has spectral type F8Ib.
Its spectrum reads F8Ib — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Rare star 35 EP
HD 166263
RA 272.6839° · Dec -22.2397° · star
Score breakdown
· 5 badgesRare 50 pts → Epic
- Supergiant +18
- Toward the galactic centre +8
- Star +3
- On the zodiac +3
- Yellow-white F-type star +3
Total score 35
15 more points to reach Epic.
Badges
- Star · +3
- Toward the galactic centre · +8
- On the zodiac · +3
- Yellow-white F-type star · +3
- Supergiant · +18
Trivia
What it actually is
- Spectral class. Its spectrum reads F8Ib — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
Find it in the sky
- How to spot it. At magnitude 7.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Sagittarius.
- Southern sky. It rides the southern half of the sky — an easier target the further south you are.
- Best time of year. It stands highest in the middle of the night around June — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.2) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 4250 K, against the Sun's 5778 K.
What's in a name
- Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.
Properties
- absmag
- -12.22
- bv
- 1.23
- constellation
- Sgr
- luminosity
- 6729766.5628
- mag
- 7.78
- name
- HD 166263
- spect
- F8Ib
Nearby objects
How to see it
Look for HD 166263 in the constellation Sgr. At apparent magnitude 7.78, it is an easy target for binoculars.
Like any astronomical target, HD 166263 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.
Why HD 166263 is a rare star
HD 166263 scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.
That score comes from 5 science badges — Star, Toward the galactic centre, On the zodiac, Yellow-white F-type star and Supergiant — 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.