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Common star 18 EP

HD 104013

RA 179.6489° · Dec -64.6299° · star

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Score breakdown

· 4 badges
18 pts · Common
Common 22 pts → Uncommon
  • Under the Southern Cross +8
  • White A-type star +5
  • Star +3
  • Main-sequence star +2
Total score 18

4 more points to reach Uncommon.

Badges

  • Star · +3
  • Under the Southern Cross · +8
  • White A-type star · +5
  • Main-sequence star · +2

Trivia

Hard to believe

  • True brightness. It pours out about 1.3 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 A0V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.

Find it in the sky

  • How to spot it. At magnitude 9.6 you'll want a small backyard telescope, over in Crux.
  • 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 March — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out brilliant white (B−V 0.1) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • 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
-10.43
bv
0.1
constellation
Cru
luminosity
1294195.8414
mag
9.57
name
HD 104013
spect
A0V

About HD 104013

HD 104013 is a common star. It sits in the constellation Cru, shines at apparent magnitude 9.57 and has spectral type A0V.

Its spectrum reads A0V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 104013 in the constellation Cru. At apparent magnitude 9.57, a small backyard telescope will bring it into view.

Like any astronomical target, HD 104013 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 104013 is a common star

HD 104013 scores 18 points on Spacedle's rarity scale, which places it in the common tier. Another 4 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Under the Southern Cross, White A-type star and Main-sequence 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.