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Epic variable star 63 EP

HD 111166

RA 191.8267° · Dec 4.1448° · star

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Score breakdown

· 6 badges
63 pts · Epic
Epic 78 pts → Anomaly
  • Carbon star (sooty red) +24
  • Dramatic variable (over 2 magnitudes) +20
  • Deep red star +8
  • Variable star +5
  • On the zodiac +3
  • A named variable star +3
Total score 63

15 more points to reach Anomaly.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • Carbon star (sooty red) · +24
  • Deep red star · +8
  • Dramatic variable (over 2 magnitudes) · +20
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 138 thousand 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 C0 — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.
  • 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 12 you'll want a small backyard telescope, over in Virgo.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • 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 4.4) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 1790 K, against the Sun's 5778 K.

Properties

absmag
-8.02
bv
4.4
constellation
Vir
luminosity
140604.7524
mag
11.98
name
HD 111166
spect
C0
var amplitude
2.11
var designation
RU
var max
10.663
var min
12.773

About HD 111166

HD 111166 is an epic variable star. It sits in the constellation Vir, shines at apparent magnitude 11.98 and has spectral type C0.

Its spectrum reads C0 — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.

How to see it

Look for HD 111166 in the constellation Vir. At apparent magnitude 11.98, a small backyard telescope will bring it into view.

Like any astronomical target, HD 111166 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 111166 is an epic variable star

HD 111166 scores 63 points on Spacedle's rarity scale, which places it in the epic tier. Another 15 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, On the zodiac, Carbon star (sooty red), Deep red star, Dramatic variable (over 2 magnitudes) 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.