About HD 200102
HD 200102 is an uncommon star. It sits in the constellation Cyg, shines at apparent magnitude 6.64 and has spectral type G1Ib.
Its spectrum reads G1Ib — a G-type star: the very same spectral class as our own Sun.
Uncommon star 29 EP
HD 200102
RA 314.9637° · Dec 44.9965° · star
Score breakdown
· 3 badgesUncommon 34 pts → Rare
- Supergiant +18
- Sun-like G-type star +8
- Star +3
Total score 29
5 more points to reach Rare.
Badges
- Star · +3
- Sun-like G-type star · +8
- Supergiant · +18
Trivia
What it actually is
- Spectral class. Its spectrum reads G1Ib — a G-type star: the very same spectral class as our own 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 6.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cygnus.
- Northern sky. It rides the northern half of the sky — an easier target the further north you are.
- Best time of year. It stands highest in the middle of the night around August — 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) — 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 4740 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
- -13.36
- bv
- 1.002
- constellation
- Cyg
- luminosity
- 19230917.2891
- mag
- 6.64
- name
- HD 200102
- spect
- G1Ib
How to see it
Look for HD 200102 in the constellation Cyg. At apparent magnitude 6.64, it is an easy target for binoculars.
Like any astronomical target, HD 200102 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 200102 is an uncommon star
HD 200102 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Sun-like G-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.