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Common star 15 EP

HD 129786

RA 221.2144° · Dec -14.3596° · star

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Score breakdown

· 4 badges
15 pts · Common
Common 22 pts → Uncommon
  • Giant star +6
  • Star +3
  • On the zodiac +3
  • Yellow-white F-type star +3
Total score 15

7 more points to reach Uncommon.

Badges

  • Star · +3
  • On the zodiac · +3
  • Yellow-white F-type star · +3
  • Giant star · +6

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 F0III/IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

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 yellow-white (B−V 0.4) — a shade brighter and crisper than our own Sun.
  • 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.

Properties

absmag
-10.83
bv
0.386
constellation
Lib
luminosity
1870682.1404
mag
9.17
name
HD 129786
spect
F0III/IV

About HD 129786

HD 129786 is a common star. It sits in the constellation Lib, shines at apparent magnitude 9.17 and has spectral type F0III/IV.

Its spectrum reads F0III/IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 129786 in the constellation Lib. At apparent magnitude 9.17, a small backyard telescope will bring it into view.

Like any astronomical target, HD 129786 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 129786 is a common star

HD 129786 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, On the zodiac, Yellow-white F-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.