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Uncommon variable star 24 EP

HD 45910

RA 97.6372° · Dec 5.8670° · star

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Score breakdown

· 5 badges
24 pts · Uncommon
Uncommon 34 pts → Rare
  • Hot blue B-type star +6
  • Giant star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 24

10 more points to reach Rare.

Badges

  • Variable star · +5
  • Hot blue B-type star · +6
  • Giant star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B2:IIIpshev — 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 6.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Monoceros.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around December — 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 0.2) — 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.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 7800 K, against the Sun's 5778 K.

Properties

absmag
-13.3
bv
0.249
constellation
Mon
luminosity
18197008.5861
mag
6.7
name
HD 45910
spect
B2:IIIpshev
var amplitude
0.16
var designation
AX
var max
6.6
var min
6.76

About HD 45910

HD 45910 is an uncommon variable star. It sits in the constellation Mon, shines at apparent magnitude 6.7 and has spectral type B2:IIIpshev.

Its spectrum reads B2:IIIpshev — 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 45910 in the constellation Mon. At apparent magnitude 6.7, it is an easy target for binoculars.

Like any astronomical target, HD 45910 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 45910 is an uncommon variable star

HD 45910 scores 24 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 10 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Hot blue B-type star, Giant 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.