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Rare variable star 34 EP

HD 7636

RA 19.3595° · Dec 57.6321° · star

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Score breakdown

· 7 badges
34 pts · Rare
Rare 50 pts → Epic
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Giant star +6
  • Variable star +5
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
Total score 34

16 more points to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Giant star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B2IIIne+... — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
  • 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.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 6.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cassiopeia.
  • 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.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Properties

absmag
-1.962
bv
0.047
constellation
Cas
dist ly
1896.2557
luminosity
530.64
mag
6.86
name
HD 7636
spect
B2IIIne+...
var amplitude
0.08
var designation
V764
var max
6.827
var min
6.907

About HD 7636

HD 7636 is a rare variable star. It lies about 1,896.3 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 6.86 and has spectral type B2IIIne+....

Its spectrum reads B2IIIne+... — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 7636 in the constellation Cas. At apparent magnitude 6.86, it is an easy target for binoculars.

Like any astronomical target, HD 7636 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 7636 is a rare variable star

HD 7636 scores 34 points on Spacedle's rarity scale, which places it in the rare tier. Another 16 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Distant (over 1,000 light-years), Never sets (northern circumpolar), Hot blue B-type star, Giant 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.