Rare star 36 EP

HD 91651

RA 158.3763° · Dec -60.1278° · star

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Score breakdown

· 4 badges

36 pts · Rare

Rare 50 pts → Epic

Blazing O-type star +26
Blue-white star +5
Star +3
Main-sequence star +2

Total score 36

14 more points to reach Epic.

Badges

Star · +3
Blazing O-type star · +26
Main-sequence star · +2
Blue-white star · +5

Trivia

Hard to believe

True brightness. It pours out about 2.5 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

Spectral class. Its spectrum reads O9Vp... — 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.

Find it in the sky

How to spot it. At magnitude 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Carina.
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 February — 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) — 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.

Properties

absmag: -11.15
bv: -0.005
constellation: Car
luminosity: 2511886.4315
mag: 8.85
name: HD 91651
spect: O9Vp...

Nearby objects

About HD 91651

HD 91651 is a rare star. It sits in the constellation Car, shines at apparent magnitude 8.85 and has spectral type O9Vp....

Its spectrum reads O9Vp... — 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 91651 in the constellation Car. At apparent magnitude 8.85, it is an easy target for binoculars.

Like any astronomical target, HD 91651 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 91651 is a rare star

HD 91651 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 4 science badges — Star, Blazing O-type star, Main-sequence star and Blue-white 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.