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Trash star 12 EP

HD 9831

RA 23.9338° · Dec -17.3033° · star

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Score breakdown

· 3 badges
12 pts · Trash
Trash 15 pts → Common
  • Giant star +6
  • Star +3
  • Orange K-type star +3
Total score 12

3 more points to reach Common.

Badges

  • Star · +3
  • Orange K-type star · +3
  • Giant star · +6

Trivia

Hard to believe

  • True brightness. It pours out about 4.1 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 K0III — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.
  • 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 8.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cetus.
  • 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 October — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.1) — 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 4560 K, against the Sun's 5778 K.

Properties

absmag
-11.7
bv
1.08
constellation
Cet
luminosity
4168693.8347
mag
8.3
name
HD 9831
spect
K0III

Nearby objects

About HD 9831

HD 9831 is a trash star. It sits in the constellation Cet, shines at apparent magnitude 8.3 and has spectral type K0III.

Its spectrum reads K0III — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 9831 in the constellation Cet. At apparent magnitude 8.3, it is an easy target for binoculars.

Like any astronomical target, HD 9831 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 9831 is a trash star

HD 9831 scores 12 points on Spacedle's rarity scale, which places it in the trash tier. Another 3 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, Orange K-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.