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Epic variable star 61 EP

Mu Cep

RA 325.8769° · Dec 58.7800° · star

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Score breakdown

· 8 badges
61 pts · Epic
Epic 78 pts → Anomaly
  • Supergiant +18
  • Strongly variable +10
  • Naked-eye visible +8
  • Deep red star +8
  • Variable star +5
  • Cool red M-type star +5
  • Never sets (northern circumpolar) +4
  • A named variable star +3
Total score 61

17 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • Cool red M-type star · +5
  • Supergiant · +18
  • Deep red star · +8
  • Strongly variable · +10
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M2Ia — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • Where it is in life. It is a luminous supergiant — among the largest and rarest stars in the galaxy.
  • 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 4.2 you can see it with your own eyes from a dark site, over in Cepheus.
  • 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 August — 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 2.2) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 2940 K, against the Sun's 5778 K.

Properties

absmag
-15.77
bv
2.242
constellation
Cep
luminosity
177010895.8317
mag
4.23
name
Mu Cep
spect
M2Ia
var amplitude
0.52
var designation
Mu
var max
3.938
var min
4.458

About Mu Cep

Mu Cep is an epic variable star. It sits in the constellation Cep, shines at apparent magnitude 4.23 and has spectral type M2Ia.

Its spectrum reads M2Ia — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.

How to see it

Look for Mu Cep in the constellation Cep. At apparent magnitude 4.23, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Mu Cep 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 Mu Cep is an epic variable star

Mu Cep scores 61 points on Spacedle's rarity scale, which places it in the epic tier. Another 17 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Naked-eye visible, Never sets (northern circumpolar), Cool red M-type star, Supergiant, Deep red star, 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.