Rare variable star 40 EP

HD 115071

RA 199.0200° · Dec -62.5837° · star

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Score breakdown

· 5 badges

40 pts · Rare

Rare 50 pts → Epic

Blazing O-type star +26
Variable star +5
Gently variable +4
A named variable star +3
Main-sequence star +2

Total score 40

10 more points to reach Epic.

Badges

Variable star · +5
Blazing O-type star · +26
Main-sequence star · +2
Gently variable · +4
A named variable star · +3

Trivia

What it actually is

Spectral class. Its spectrum reads O9.5V — 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 8 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 April — 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.

Properties

absmag: -12.05
bv: 0.226
constellation: Cen
luminosity: 5754399.3734
mag: 7.95
name: HD 115071
spect: O9.5V
var amplitude: 0.1
var designation: V961
var max: 7.904
var min: 8.004

Nearby objects

About HD 115071

HD 115071 is a rare variable star. It sits in the constellation Cen, shines at apparent magnitude 7.95 and has spectral type O9.5V.

Its spectrum reads O9.5V — 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 115071 in the constellation Cen. At apparent magnitude 7.95, it is an easy target for binoculars.

Like any astronomical target, HD 115071 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 115071 is a rare variable star

HD 115071 scores 40 points on Spacedle's rarity scale, which places it in the rare tier. Another 10 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Blazing O-type star, Main-sequence 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.