About HD 103807
HD 103807 is an uncommon star. It sits in the constellation Cru, shines at apparent magnitude 7.59 and has spectral type F7Ib-II.
Its spectrum reads F7Ib-II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Uncommon star 32 EP
HD 103807
RA 179.2782° · Dec -63.6767° · star
Score breakdown
· 4 badgesUncommon 34 pts → Rare
- Supergiant +18
- Under the Southern Cross +8
- Star +3
- Yellow-white F-type star +3
Total score 32
2 more points to reach Rare.
Badges
- Star · +3
- Under the Southern Cross · +8
- Yellow-white F-type star · +3
- Supergiant · +18
Trivia
What it actually is
- Spectral class. Its spectrum reads F7Ib-II — an F-type star — a little hotter, whiter and shorter-lived than the 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 7.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Crux.
- Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
- Best time of year. It stands highest in the middle of the night around March — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.6) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
- 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 5790 K, against the Sun's 5778 K.
Properties
- absmag
- -12.41
- bv
- 0.646
- constellation
- Cru
- luminosity
- 8016780.6339
- mag
- 7.59
- name
- HD 103807
- spect
- F7Ib-II
How to see it
Look for HD 103807 in the constellation Cru. At apparent magnitude 7.59, it is an easy target for binoculars.
Like any astronomical target, HD 103807 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 103807 is an uncommon star
HD 103807 scores 32 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 2 points would lift it into a rarer tier.
That score comes from 4 science badges — Star, Under the Southern Cross, Yellow-white F-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.