About HD 251807
HD 251807 is a trash star. It sits in the constellation Aur, shines at apparent magnitude 9.54 and has spectral type F2.
Its spectrum reads F2 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Trash star 6 EP
HD 251807
RA 91.9150° · Dec 28.4721° · star
Score breakdown
· 2 badgesTrash 15 pts → Common
- Star +3
- Yellow-white F-type star +3
Total score 6
9 more points to reach Common.
Badges
- Star · +3
- Yellow-white F-type star · +3
Trivia
Hard to believe
- True brightness. It pours out about 1.3 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 F2 — 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 9.5 you'll want a small backyard telescope, over in Auriga.
- 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 December — 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 6780 K, against the Sun's 5778 K.
Properties
- absmag
- -10.46
- bv
- 0.42
- constellation
- Aur
- luminosity
- 1330454.418
- mag
- 9.54
- name
- HD 251807
- spect
- F2
How to see it
Look for HD 251807 in the constellation Aur. At apparent magnitude 9.54, a small backyard telescope will bring it into view.
Like any astronomical target, HD 251807 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 251807 is a trash star
HD 251807 scores 6 points on Spacedle's rarity scale, which places it in the trash tier. Another 9 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and Yellow-white F-type 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.