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Uncommon star 24 EP

HD 21902

RA 55.3695° · Dec 79.5353° · star

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Score breakdown

· 5 badges
24 pts · Uncommon
Uncommon 34 pts → Rare
  • Deep red star +8
  • Distant (over 1,000 light-years) +6
  • Never sets (northern circumpolar) +4
  • Star +3
  • Orange K-type star +3
Total score 24

10 more points to reach Rare.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Orange K-type star · +3
  • Deep red star · +8

Trivia

What it actually is

  • Spectral class. Its spectrum reads K0 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

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 8.3 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 November — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 35.4 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 3.1 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
-0.682
bv
1.576
constellation
Cep
dist ly
2013.3088
luminosity
163.23
mag
8.27
name
HD 21902
spect
K0

About HD 21902

HD 21902 is an uncommon star. It lies about 2,013.3 light-years from Earth, sits in the constellation Cep, shines at apparent magnitude 8.27 and has spectral type K0.

Its spectrum reads K0 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 21902 in the constellation Cep. At apparent magnitude 8.27, it is an easy target for binoculars.

Like any astronomical target, HD 21902 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 21902 is an uncommon star

HD 21902 scores 24 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 10 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Distant (over 1,000 light-years), Never sets (northern circumpolar), Orange K-type star and Deep red 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.