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Rare star 35 EP

HD 140543

RA 236.2361° · Dec -21.8150° · star

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Score breakdown

· 5 badges
35 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
  • On the zodiac +3
Total score 35

15 more points to reach Epic.

Badges

  • Star · +3
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Blue-white star · +5

Trivia

Hard to believe

  • True brightness. It pours out about 2.4 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 B1Iabn — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a supergiant. Drop it where the Sun is and its surface would engulf the inner planets.

Find it in the sky

  • How to spot it. At magnitude 8.9 it is just past naked-eye reach — ordinary binoculars will pull it in, 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 blue-white (B−V -0) — the hallmark of a surface far hotter than the Sun's.
  • 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
-11.13
bv
-0.017
constellation
Lib
luminosity
2466039.3372
mag
8.87
name
HD 140543
spect
B1Iabn

About HD 140543

HD 140543 is a rare star. It sits in the constellation Lib, shines at apparent magnitude 8.87 and has spectral type B1Iabn.

Its spectrum reads B1Iabn — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 140543 in the constellation Lib. At apparent magnitude 8.87, it is an easy target for binoculars.

Like any astronomical target, HD 140543 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 140543 is a rare star

HD 140543 scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, On the zodiac, Hot blue B-type star, Supergiant and Blue-white 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.