Rare variable star 38 EP

HD 101205

RA 174.5849° · Dec -63.3727° · star

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Score breakdown

· 4 badges

38 pts · Rare

Rare 50 pts → Epic

Blazing O-type star +26
Variable star +5
Gently variable +4
A named variable star +3

Total score 38

12 more points to reach Epic.

Badges

Variable star · +5
Blazing O-type star · +26
Gently variable · +4
A named variable star · +3

Trivia

What it actually is

Spectral class. Its spectrum reads O8var — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.
Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
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 6.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Centaurus.
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 brilliant white (B−V 0) — 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.

Properties

absmag: -13.54
bv: 0.043
constellation: Cen
luminosity: 22698648.5188
mag: 6.46
name: HD 101205
spect: O8var
var amplitude: 0.09
var designation: V871
var max: 6.434
var min: 6.524

Nearby objects

About HD 101205

HD 101205 is a rare variable star. It sits in the constellation Cen, shines at apparent magnitude 6.46 and has spectral type O8var.

Its spectrum reads O8var — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

How to see it

Look for HD 101205 in the constellation Cen. At apparent magnitude 6.46, it is an easy target for binoculars.

Like any astronomical target, HD 101205 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 101205 is a rare variable star

HD 101205 scores 38 points on Spacedle's rarity scale, which places it in the rare tier. Another 12 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Blazing O-type 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.