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Common variable star 20 EP

HD 10636

RA 26.2917° · Dec 53.9524° · star

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Score breakdown

· 4 badges
20 pts · Common
Common 22 pts → Uncommon
  • Deep red star +8
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • Deep red star · +8
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 946.2 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 R6 — 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 9.9 you'll want a small backyard telescope, over in Perseus.
  • 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 October — 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 1.7) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3490 K, against the Sun's 5778 K.

Properties

absmag
-10.11
bv
1.722
constellation
Per
luminosity
963829.0236
mag
9.89
name
HD 10636
spect
R6
var amplitude
0.15
var designation
V547
var max
9.807
var min
9.957

About HD 10636

HD 10636 is a common variable star. It sits in the constellation Per, shines at apparent magnitude 9.89 and has spectral type R6.

Its spectrum reads R6 — 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 10636 in the constellation Per. At apparent magnitude 9.89, a small backyard telescope will bring it into view.

Like any astronomical target, HD 10636 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 10636 is a common variable star

HD 10636 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable 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.