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Uncommon star 25 EP

HR 2633

RA 105.4803° · Dec 5.5572° · star

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Score breakdown

· 5 badges
25 pts · Uncommon
Uncommon 34 pts → Rare
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
Total score 25

9 more points to reach Rare.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B2IV-V — 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 subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

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 6.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Monoceros.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around January — 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. ≈ 23.7 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.491
bv
-0.028
constellation
Mon
dist ly
1347.7519
luminosity
343.8745
mag
6.59
name
HR 2633
spect
B2IV-V

About HR 2633

HR 2633 is an uncommon star. It lies about 1,347.8 light-years from Earth, sits in the constellation Mon, shines at apparent magnitude 6.59 and has spectral type B2IV-V.

Its spectrum reads B2IV-V — 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 2633 in the constellation Mon. At apparent magnitude 6.59, it is an easy target for binoculars.

Like any astronomical target, HR 2633 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 2633 is an uncommon star

HR 2633 scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Distant (over 1,000 light-years), Hot blue B-type star, Subgiant (leaving the main sequence) 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.