About HD 177243
HD 177243 is an uncommon star. It sits in the constellation Sgr, shines at apparent magnitude 8.66 and has spectral type F3IV/V.
Its spectrum reads F3IV/V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Uncommon star 22 EP
HD 177243
RA 286.3255° · Dec -33.0180° · star
Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Toward the galactic centre +8
- Subgiant (leaving the main sequence) +5
- Star +3
- On the zodiac +3
- Yellow-white F-type star +3
Total score 22
12 more points to reach Rare.
Badges
- Star · +3
- Toward the galactic centre · +8
- On the zodiac · +3
- Yellow-white F-type star · +3
- Subgiant (leaving the main sequence) · +5
Trivia
Hard to believe
- True brightness. It pours out about 2.9 million 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 F3IV/V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.
Find it in the sky
- How to spot it. At magnitude 8.7 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 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 0.5) — 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.
Properties
- absmag
- -11.34
- bv
- 0.471
- constellation
- Sgr
- luminosity
- 2992264.6366
- mag
- 8.66
- name
- HD 177243
- spect
- F3IV/V
How to see it
Look for HD 177243 in the constellation Sgr. At apparent magnitude 8.66, it is an easy target for binoculars.
Like any astronomical target, HD 177243 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 177243 is an uncommon star
HD 177243 scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 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 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.