About HD 186
HD 186 is a trash star. It sits in the constellation And, shines at apparent magnitude 9 and has spectral type F5.
Its spectrum reads F5 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Trash star 11 EP
HD 186
RA 1.6998° · Dec 44.6128° · star
Score breakdown
· 3 badgesTrash 15 pts → Common
- Blue-white star +5
- Star +3
- Yellow-white F-type star +3
Total score 11
4 more points to reach Common.
Badges
- Star · +3
- Yellow-white F-type star · +3
- Blue-white star · +5
Trivia
Hard to believe
- True brightness. It pours out about 2.1 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 F5 — 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 9 you'll want a small backyard telescope, over in Andromeda.
- 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 September — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out blue-white (B−V -0.1) — the hallmark of a surface far hotter than the Sun's.
- 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 11410 K, against the Sun's 5778 K.
Properties
- absmag
- -11
- bv
- -0.09
- constellation
- And
- luminosity
- 2187761.6239
- mag
- 9
- name
- HD 186
- spect
- F5
How to see it
Look for HD 186 in the constellation And. At apparent magnitude 9, it is an easy target for binoculars.
Like any astronomical target, HD 186 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 186 is a trash star
HD 186 scores 11 points on Spacedle's rarity scale, which places it in the trash tier. Another 4 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Yellow-white F-type star and Blue-white 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.