About HD 137743
HD 137743 is an uncommon star. It sits in the constellation Lib, shines at apparent magnitude 9.22 and has spectral type G3/G5.
Its spectrum reads G3/G5 — a G-type star: the very same spectral class as our own Sun.
Uncommon star 22 EP
HD 137743
RA 232.0258° · Dec -13.5185° · star
Score breakdown
· 4 badgesUncommon 34 pts → Rare
- Sun-like G-type star +8
- Deep red star +8
- Star +3
- On the zodiac +3
Total score 22
12 more points to reach Rare.
Badges
- Star · +3
- On the zodiac · +3
- Sun-like G-type star · +8
- Deep red star · +8
Trivia
Hard to believe
- True brightness. It pours out about 1.8 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/G5 — a G-type star: the very same spectral class as our own Sun.
Find it in the sky
- How to spot it. At magnitude 9.2 you'll want a small backyard telescope, over in Libra.
- 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 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 3940 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
- -10.78
- bv
- 1.408
- constellation
- Lib
- luminosity
- 1786487.5749
- mag
- 9.22
- name
- HD 137743
- spect
- G3/G5
How to see it
Look for HD 137743 in the constellation Lib. At apparent magnitude 9.22, a small backyard telescope will bring it into view.
Like any astronomical target, HD 137743 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 137743 is an uncommon star
HD 137743 scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 points would lift it into a rarer tier.
That score comes from 4 science badges — Star, On the zodiac, 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.