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Common star 19 EP

HD 99966

RA 172.6243° · Dec 48.9357° · star

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Score breakdown

· 5 badges
19 pts · Common
Common 22 pts → Uncommon
  • White A-type star +5
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Star +3
  • Main-sequence star +2
Total score 19

3 more points to reach Uncommon.

Badges

  • Star · +3
  • 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 7.4 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 March — 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. ≈ 12.9 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.637
bv
-0.044
constellation
UMa
dist ly
731.2913
luminosity
48.4395
mag
7.39
name
HD 99966
spect
A0V

About HD 99966

HD 99966 is a common star. It lies about 731.3 light-years from Earth, sits in the constellation UMa, shines at apparent magnitude 7.39 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 HD 99966 in the constellation UMa. At apparent magnitude 7.39, it is an easy target for binoculars.

Like any astronomical target, HD 99966 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 99966 is a common star

HD 99966 scores 19 points on Spacedle's rarity scale, which places it in the common tier. Another 3 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, 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.