About HD 143817
HD 143817 is a common star. It sits in the constellation Nor, shines at apparent magnitude 7.49 and has spectral type F7II.
Its spectrum reads F7II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Common star 18 EP
HD 143817
RA 241.3263° · Dec -55.8112° · star
Score breakdown
· 3 badgesCommon 22 pts → Uncommon
- Bright giant +12
- Star +3
- Yellow-white F-type star +3
Total score 18
4 more points to reach Uncommon.
Badges
- Star · +3
- Yellow-white F-type star · +3
- Bright giant · +12
Trivia
What it actually is
- Spectral class. Its spectrum reads F7II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a bright giant, well on its way to the largest stars there are.
Find it in the sky
- How to spot it. At magnitude 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Norma.
- 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 May — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out orange (B−V 0.8) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
- 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 5160 K, against the Sun's 5778 K.
Properties
- absmag
- -12.51
- bv
- 0.84
- constellation
- Nor
- luminosity
- 8790225.1683
- mag
- 7.49
- name
- HD 143817
- spect
- F7II
How to see it
Look for HD 143817 in the constellation Nor. At apparent magnitude 7.49, it is an easy target for binoculars.
Like any astronomical target, HD 143817 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 143817 is a common star
HD 143817 scores 18 points on Spacedle's rarity scale, which places it in the common 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 Bright giant — 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.