Rare variable star 39 EP

HD 166126

RA 272.4610° · Dec -15.5501° · star

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Score breakdown

· 5 badges

39 pts · Rare

Rare 50 pts → Epic

Supergiant +18
Strongly variable +10
Variable star +5
Yellow-white F-type star +3
A named variable star +3

Total score 39

11 more points to reach Epic.

Badges

Variable star · +5
Yellow-white F-type star · +3
Supergiant · +18
Strongly variable · +10
A named variable star · +3

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 F8/G2Iaep+A: — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
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 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Serpens.
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 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: -11.16
bv: 0.698
constellation: Ser
luminosity: 2535128.6305
mag: 8.84
name: HD 166126
spect: F8/G2Iaep+A:
var amplitude: 0.83
var designation: W
var max: 8.598
var min: 9.428

Nearby objects

About HD 166126

HD 166126 is a rare variable star. It sits in the constellation Ser, shines at apparent magnitude 8.84 and has spectral type F8/G2Iaep+A:.

Its spectrum reads F8/G2Iaep+A: — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 166126 in the constellation Ser. At apparent magnitude 8.84, it is an easy target for binoculars.

Like any astronomical target, HD 166126 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 166126 is a rare variable star

HD 166126 scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Yellow-white F-type star, Supergiant, Strongly 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.