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Common star 21 EP

HR 9105

RA 1.1524° · Dec 42.0925° · star

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Score breakdown

· 4 badges
21 pts · Common
Common 22 pts → Uncommon
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Giant star +6
  • Star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.

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 6.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Andromeda.
  • 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 September — 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. ≈ 22.1 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.824
bv
0.159
constellation
And
dist ly
1259.2896
luminosity
467.3045
mag
6.11
name
HR 9105
spect
B9III

About HR 9105

HR 9105 is a common star. It lies about 1,259.3 light-years from Earth, sits in the constellation And, shines at apparent magnitude 6.11 and has spectral type B9III.

Its spectrum reads B9III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HR 9105 in the constellation And. At apparent magnitude 6.11, it is an easy target for binoculars.

Like any astronomical target, HR 9105 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 HR 9105 is a common star

HR 9105 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 4 science badges — Star, Distant (over 1,000 light-years), Hot blue B-type star and Giant 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.