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Common star 18 EP

HIP 7641

RA 24.6095° · Dec 62.5092° · star

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Score breakdown

· 4 badges
18 pts · Common
Common 22 pts → Uncommon
  • Deep red star +8
  • Never sets (northern circumpolar) +4
  • Star +3
  • Orange K-type star +3
Total score 18

4 more points to reach Uncommon.

Badges

  • Star · +3
  • Never sets (northern circumpolar) · +4
  • Orange K-type star · +3
  • Deep red star · +8

Trivia

Hard to believe

  • True brightness. It pours out about 1.1 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 K5 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

Find it in the sky

  • How to spot it. At magnitude 9.7 you'll want a small backyard telescope, over in Cassiopeia.
  • 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 October — 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 1.6) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3680 K, against the Sun's 5778 K.

What's in a name

  • Its catalogue. The HIP number comes from Hipparcos, the ESA satellite that between 1989 and 1993 pinned down 118,000 stars precisely enough to triangulate their distances.

Properties

absmag
-10.31
bv
1.58
constellation
Cas
luminosity
1158777.3562
mag
9.69
name
HIP 7641
spect
K5

About HIP 7641

HIP 7641 is a common star. It sits in the constellation Cas, shines at apparent magnitude 9.69 and has spectral type K5.

Its spectrum reads K5 — 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 HIP 7641 in the constellation Cas. At apparent magnitude 9.69, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 7641 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 7641 is a common star

HIP 7641 scores 18 points on Spacedle's rarity scale, which places it in the common tier. Another 4 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, 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.