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Rare variable star 44 EP

HIP 68837

RA 211.4268° · Dec -67.0152° · star

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Score breakdown

· 5 badges
44 pts · Rare
Rare 50 pts → Epic
  • Carbon star (sooty red) +24
  • Deep red star +8
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 44

6 more points to reach Epic.

Badges

  • Variable star · +5
  • Carbon star (sooty red) · +24
  • Deep red star · +8
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1.3 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 C — 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 9.5 you'll want a small backyard telescope, over in Circinus.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • 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 2.1) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3070 K, against the Sun's 5778 K.

Properties

absmag
-10.46
bv
2.1
constellation
Cir
luminosity
1330454.418
mag
9.54
name
HIP 68837
spect
C
var amplitude
0.27
var designation
U
var max
9.411
var min
9.681

About HIP 68837

HIP 68837 is a rare variable star. It sits in the constellation Cir, shines at apparent magnitude 9.54 and has spectral type C.

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

How to see it

Look for HIP 68837 in the constellation Cir. At apparent magnitude 9.54, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 68837 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 HIP 68837 is a rare variable star

HIP 68837 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Carbon star (sooty red), 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.