Uncommon variable star 27 EP

HD 234102

RA 211.0726° · Dec 51.4551° · star

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Score breakdown

· 6 badges

27 pts · Uncommon

Uncommon 34 pts → Rare

Deep red star +8
Variable star +5
Never sets (northern circumpolar) +4
Gently variable +4
Orange K-type star +3
A named variable star +3

Total score 27

7 more points to reach Rare.

Badges

Variable star · +5
Never sets (northern circumpolar) · +4
Orange K-type star · +3
Deep red star · +8
Gently variable · +4
A named variable star · +3

Trivia

Hard to believe

True brightness. It pours out about 3 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 K7 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.
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 8.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Ursa Major.
Northern sky. It rides the northern half of the sky — an easier target the further north you are.
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 deep orange-red (B−V 1.6) — one of the coolest surfaces a star can have while still fusing.

By the numbers

Surface temperature. Its colour puts the surface at roughly 3700 K, against the Sun's 5778 K.

Properties

absmag: -11.35
bv: 1.562
constellation: UMa
luminosity: 3019951.7204
mag: 8.65
name: HD 234102
spect: K7
var amplitude: 0.16
var designation: IT
var max: 8.574
var min: 8.734

Nearby objects

About HD 234102

HD 234102 is an uncommon variable star. It sits in the constellation UMa, shines at apparent magnitude 8.65 and has spectral type K7.

Its spectrum reads K7 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 234102 in the constellation UMa. At apparent magnitude 8.65, it is an easy target for binoculars.

Like any astronomical target, HD 234102 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 234102 is an uncommon variable star

HD 234102 scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Never sets (northern circumpolar), Orange K-type star, Deep red 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.