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Rare variable star 47 EP

HIP 103656

RA 315.0266° · Dec 42.5976° · star

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Score breakdown

· 6 badges
47 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Strongly variable +10
  • Deep red star +8
  • Variable star +5
  • Yellow-white F-type star +3
  • A named variable star +3
Total score 47

3 more points to reach Epic.

Badges

  • Variable star · +5
  • Yellow-white F-type star · +3
  • Supergiant · +18
  • Deep red star · +8
  • Strongly variable · +10
  • 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 F5.5Ibv — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
  • 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 Cygnus.
  • 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.

Properties

absmag
-10.47
bv
2.18
constellation
Cyg
luminosity
1342764.9611
mag
9.53
name
HIP 103656
spect
F5.5Ibv
var amplitude
1.04
var designation
TX
var max
8.852
var min
9.892

About HIP 103656

HIP 103656 is a rare variable star. It sits in the constellation Cyg, shines at apparent magnitude 9.53 and has spectral type F5.5Ibv.

Its spectrum reads F5.5Ibv — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HIP 103656 in the constellation Cyg. At apparent magnitude 9.53, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 103656 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 103656 is a rare variable star

HIP 103656 scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Yellow-white F-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.