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Common variable star 21 EP

HD 217796

RA 345.5234° · Dec 62.5121° · star

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Score breakdown

· 5 badges
21 pts · Common
Common 22 pts → Uncommon
  • Variable star +5
  • White A-type star +5
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Variable star · +5
  • Never sets (northern circumpolar) · +4
  • White A-type star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A5 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • 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 8.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cepheus.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 13.7 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.241
bv
0.412
constellation
Cep
dist ly
782.1488
luminosity
27.7715
mag
8.14
name
HD 217796
spect
A5
var amplitude
0.34
var designation
NN
var max
8.086
var min
8.426

About HD 217796

HD 217796 is a common variable star. It lies about 782.1 light-years from Earth, sits in the constellation Cep, shines at apparent magnitude 8.14 and has spectral type A5.

Its spectrum reads A5 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 217796 in the constellation Cep. At apparent magnitude 8.14, it is an easy target for binoculars.

Like any astronomical target, HD 217796 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 217796 is a common variable star

HD 217796 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Never sets (northern circumpolar), White A-type 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.