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Rare variable star 36 EP

HD 75860

RA 132.7218° · Dec -43.7515° · star

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Score breakdown

· 5 badges
36 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 36

14 more points to reach Epic.

Badges

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

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1.5Iab — 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.
  • 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 7.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Vela.
  • 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 February — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.7) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
  • 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
-12.42
bv
0.716
constellation
Vel
luminosity
8090958.9918
mag
7.58
name
HD 75860
spect
B1.5Iab
var amplitude
0.09
var designation
OS
var max
7.539
var min
7.629

About HD 75860

HD 75860 is a rare variable star. It sits in the constellation Vel, shines at apparent magnitude 7.58 and has spectral type B1.5Iab.

Its spectrum reads B1.5Iab — 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 75860 in the constellation Vel. At apparent magnitude 7.58, it is an easy target for binoculars.

Like any astronomical target, HD 75860 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 75860 is a rare variable star

HD 75860 scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 14 points would lift it into a rarer tier.

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