About HD 137022
HD 137022 is a common star. It sits in the constellation Cir, shines at apparent magnitude 8.81 and has spectral type G3/G5III.
Its spectrum reads G3/G5III — a G-type star: the very same spectral class as our own Sun.
Common star 17 EP
HD 137022
RA 231.6849° · Dec -60.6147° · star
Score breakdown
· 3 badgesCommon 22 pts → Uncommon
- Sun-like G-type star +8
- Giant star +6
- Star +3
Total score 17
5 more points to reach Uncommon.
Badges
- Star · +3
- Sun-like G-type star · +8
- Giant star · +6
Trivia
Hard to believe
- True brightness. It pours out about 2.6 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 G3/G5III — a G-type star: the very same spectral class as our own Sun.
Find it in the sky
- How to spot it. At magnitude 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Circinus.
- 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 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 1.2) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 4320 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
- -11.19
- bv
- 1.194
- constellation
- Cir
- luminosity
- 2606153.55
- mag
- 8.81
- name
- HD 137022
- spect
- G3/G5III
How to see it
Look for HD 137022 in the constellation Cir. At apparent magnitude 8.81, it is an easy target for binoculars.
Like any astronomical target, HD 137022 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 137022 is a common star
HD 137022 scores 17 points on Spacedle's rarity scale, which places it in the common tier. Another 5 points would lift it into a rarer tier.
That score comes from 3 science badges — Star, Sun-like G-type star and Giant 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.