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Uncommon star 27 EP

81 UMa

RA 203.5305° · Dec 55.3484° · star

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Score breakdown

· 6 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • White A-type star +5
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Star +3
  • Main-sequence star +2
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • Never sets (northern circumpolar) · +4
  • White A-type star · +5
  • Main-sequence star · +2
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads A0V — 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.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.

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 5.6 you can see it with your own eyes from a dark site, over in Ursa Major.
  • 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 April — 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. ≈ 5.2 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.791
bv
-0.014
constellation
UMa
dist ly
298.6777
luminosity
42.0339
mag
5.6
name
81 UMa
spect
A0V

About 81 UMa

81 UMa is an uncommon star. It lies about 298.7 light-years from Earth, sits in the constellation UMa, shines at apparent magnitude 5.6 and has spectral type A0V.

Its spectrum reads A0V — 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 81 UMa in the constellation UMa. At apparent magnitude 5.6, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 81 UMa 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 81 UMa is an uncommon star

81 UMa scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, Never sets (northern circumpolar), White A-type star, Main-sequence star and Blue-white 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.