About HD 247040
HD 247040 is a common star. It sits in the constellation Aur, shines at apparent magnitude 11.09 and has spectral type G0.
Its spectrum reads G0 — a G-type star: the very same spectral class as our own Sun.
Common star 19 EP
HD 247040
RA 86.3722° · Dec 32.2278° · star
Score breakdown
· 3 badgesCommon 22 pts → Uncommon
- Sun-like G-type star +8
- Deep red star +8
- Star +3
Total score 19
3 more points to reach Uncommon.
Badges
- Star · +3
- Sun-like G-type star · +8
- Deep red star · +8
Trivia
Hard to believe
- True brightness. It pours out about 313.3 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 G0 — a G-type star: the very same spectral class as our own Sun.
Find it in the sky
- How to spot it. At magnitude 11.1 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 deep orange-red (B−V 1.6) — one of the coolest surfaces a star can have while still fusing.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 3600 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
- -8.91
- bv
- 1.634
- constellation
- Aur
- luminosity
- 319153.7855
- mag
- 11.09
- name
- HD 247040
- spect
- G0
How to see it
Look for HD 247040 in the constellation Aur. At apparent magnitude 11.09, a small backyard telescope will bring it into view.
Like any astronomical target, HD 247040 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 247040 is a common star
HD 247040 scores 19 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Sun-like G-type star 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.