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Common star 16 EP

HD 105541

RA 182.3088° · Dec -60.4940° · star

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Score breakdown

· 4 badges
16 pts · Common
Common 22 pts → Uncommon
  • Under the Southern Cross +8
  • Star +3
  • Yellow-white F-type star +3
  • Main-sequence star +2
Total score 16

6 more points to reach Uncommon.

Badges

  • Star · +3
  • Under the Southern Cross · +8
  • Yellow-white F-type star · +3
  • Main-sequence star · +2

Trivia

Hard to believe

  • True brightness. It pours out about 2.1 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 F0V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • 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 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 yellow-white (B−V 0.5) — 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
-11
bv
0.477
constellation
Cru
luminosity
2187761.6239
mag
9
name
HD 105541
spect
F0V

About HD 105541

HD 105541 is a common star. It sits in the constellation Cru, shines at apparent magnitude 9 and has spectral type F0V.

Its spectrum reads F0V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 105541 in the constellation Cru. At apparent magnitude 9, it is an easy target for binoculars.

Like any astronomical target, HD 105541 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 105541 is a common star

HD 105541 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Under the Southern Cross, Yellow-white F-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.