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Common variable star 21 EP

HD 81995

RA 142.6597° · Dec 44.7694° · 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 7.3 it is just past naked-eye reach — ordinary binoculars will pull it in, 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 February — 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. ≈ 9.3 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.277
bv
0.205
constellation
UMa
dist ly
532.0651
luminosity
26.8658
mag
7.34
name
HD 81995
spect
A5
var amplitude
0.06
var designation
QR
var max
7.321
var min
7.381

About HD 81995

HD 81995 is a common variable star. It lies about 532.1 light-years from Earth, sits in the constellation UMa, shines at apparent magnitude 7.34 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 81995 in the constellation UMa. At apparent magnitude 7.34, it is an easy target for binoculars.

Like any astronomical target, HD 81995 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 81995 is a common variable star

HD 81995 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.