Uncommon star 26 EP

HD 166140

RA 273.0015° · Dec -51.6535° · star

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Score breakdown

· 4 badges

26 pts · Uncommon

Uncommon 34 pts → Rare

Bright giant +12
Hot blue B-type star +6
Blue-white star +5
Star +3

Total score 26

8 more points to reach Rare.

Badges

Star · +3
Hot blue B-type star · +6
Bright giant · +12
Blue-white star · +5

Trivia

Hard to believe

True brightness. It pours out about 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 B8II/III — 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 bright giant, well on its way to the largest stars there are.

Find it in the sky

How to spot it. At magnitude 8.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Telescopium.
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 June — 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 -0.1) — 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: -11.91
bv: -0.079
constellation: Tel
luminosity: 5058246.62
mag: 8.09
name: HD 166140
spect: B8II/III

Nearby objects

About HD 166140

HD 166140 is an uncommon star. It sits in the constellation Tel, shines at apparent magnitude 8.09 and has spectral type B8II/III.

Its spectrum reads B8II/III — 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 166140 in the constellation Tel. At apparent magnitude 8.09, it is an easy target for binoculars.

Like any astronomical target, HD 166140 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 166140 is an uncommon star

HD 166140 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Hot blue B-type star, Bright giant 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.