About HD 129431
HD 129431 is a trash star. It sits in the constellation Vir and shines at apparent magnitude 9.68.
Its colour puts the surface at roughly 5220 K, against the Sun's 5778 K.
Trash star 6 EP
HD 129431
RA 220.6720° · Dec -5.9692° · star
Score breakdown
· 2 badgesTrash 15 pts → Common
- Star +3
- On the zodiac +3
Total score 6
9 more points to reach Common.
Badges
- Star · +3
- On the zodiac · +3
Trivia
Hard to believe
- True brightness. It pours out about 1.1 million times as much light as the Sun. It only looks ordinary because it is so far away.
Find it in the sky
- How to spot it. At magnitude 9.7 you'll want a small backyard telescope, over in Virgo.
- Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
- 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 0.8) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
- 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.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 5220 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
- -10.32
- bv
- 0.821
- constellation
- Vir
- luminosity
- 1169499.391
- mag
- 9.68
- name
- HD 129431
How to see it
Look for HD 129431 in the constellation Vir. At apparent magnitude 9.68, a small backyard telescope will bring it into view.
Like any astronomical target, HD 129431 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 129431 is a trash star
HD 129431 scores 6 points on Spacedle's rarity scale, which places it in the trash tier. Another 9 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and On the zodiac — 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.