About HD 184647
HD 184647 is a common star. It sits in the constellation Sgr, shines at apparent magnitude 10.29 and has spectral type F2/F3V.
Its spectrum reads F2/F3V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Common star 19 EP
HD 184647
RA 294.1540° · Dec -31.2593° · star
Score breakdown
· 5 badgesCommon 22 pts → Uncommon
- Toward the galactic centre +8
- Star +3
- On the zodiac +3
- Yellow-white F-type star +3
- Main-sequence star +2
Total score 19
3 more points to reach Uncommon.
Badges
- Star · +3
- Toward the galactic centre · +8
- On the zodiac · +3
- Yellow-white F-type star · +3
- Main-sequence star · +2
Trivia
Hard to believe
- True brightness. It pours out about 654.6 thousand times as much light as the Sun. It only looks ordinary because it is so far away.
What it actually is
- Spectral class. Its spectrum reads F2/F3V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Find it in the sky
- How to spot it. At magnitude 10.3 you'll want a small backyard telescope, 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 July — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow-white (B−V 0.4) — a shade brighter and crisper than our own Sun.
- Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 6640 K, against the Sun's 5778 K.
Properties
- absmag
- -9.71
- bv
- 0.446
- constellation
- Sgr
- luminosity
- 666806.7692
- mag
- 10.29
- name
- HD 184647
- spect
- F2/F3V
How to see it
Look for HD 184647 in the constellation Sgr. At apparent magnitude 10.29, a small backyard telescope will bring it into view.
Like any astronomical target, HD 184647 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 184647 is a common star
HD 184647 scores 19 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 5 science badges — Star, Toward the galactic centre, On the zodiac, Yellow-white F-type star and Main-sequence 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.