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Rare variable star 41 EP

HD 58011

RA 110.6805° · Dec -26.0113° · star

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Score breakdown

· 6 badges
41 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • Gently variable +4
  • A named variable star +3
Total score 41

9 more points to reach Epic.

Badges

  • Variable star · +5
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Blue-white star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1/B2Ib/IIn — 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.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Find it in the sky

  • How to spot it. At magnitude 7.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Canis Major.
  • 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 January — 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 -0.1) — 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.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 11140 K, against the Sun's 5778 K.

Properties

absmag
-12.85
bv
-0.073
constellation
CMa
luminosity
12022644.3462
mag
7.15
name
HD 58011
spect
B1/B2Ib/IIn
var amplitude
0.25
var designation
NN
var max
7.06
var min
7.31

About HD 58011

HD 58011 is a rare variable star. It sits in the constellation CMa, shines at apparent magnitude 7.15 and has spectral type B1/B2Ib/IIn.

Its spectrum reads B1/B2Ib/IIn — 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 58011 in the constellation CMa. At apparent magnitude 7.15, it is an easy target for binoculars.

Like any astronomical target, HD 58011 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 58011 is a rare variable star

HD 58011 scores 41 points on Spacedle's rarity scale, which places it in the rare tier. Another 9 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Hot blue B-type star, Supergiant, Blue-white star, Gently variable and A named variable 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.