About HD 170282
HD 170282 is a rare star. It sits in the constellation CrA, shines at apparent magnitude 9.88 and has spectral type C.
Its spectrum reads C — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.
Rare star 35 EP
HD 170282
RA 277.5633° · Dec -38.4170° · star
Score breakdown
· 3 badgesRare 50 pts → Epic
- Carbon star (sooty red) +24
- Deep red star +8
- Star +3
Total score 35
15 more points to reach Epic.
Badges
- Star · +3
- Carbon star (sooty red) · +24
- Deep red star · +8
Trivia
Hard to believe
- True brightness. It pours out about 955 thousand 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 C — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.
Find it in the sky
- How to spot it. At magnitude 9.9 you'll want a small backyard telescope, over in Corona Australis.
- 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 June — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 1.4) — one of the coolest surfaces a star can have while still fusing.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 3900 K, against the Sun's 5778 K.
What's in a name
- Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.
Properties
- absmag
- -10.12
- bv
- 1.43
- constellation
- CrA
- luminosity
- 972747.2238
- mag
- 9.88
- name
- HD 170282
- spect
- C
How to see it
Look for HD 170282 in the constellation CrA. At apparent magnitude 9.88, a small backyard telescope will bring it into view.
Like any astronomical target, HD 170282 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 170282 is a rare star
HD 170282 scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Carbon star (sooty red) and Deep red 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.