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Uncommon star 30 EP

HD 47417

RA 99.6997° · Dec 6.9019° · star

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Score breakdown

· 5 badges
30 pts · Uncommon
Uncommon 34 pts → Rare
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Star +3
Total score 30

4 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
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads B0IV — 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 6.9 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 December — 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. ≈ 49.4 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-2.738
bv
0.003
constellation
Mon
dist ly
2811.6898
luminosity
1084.4262
mag
6.94
name
HD 47417
spect
B0IV

About HD 47417

HD 47417 is an uncommon star. It lies about 2,811.7 light-years from Earth, sits in the constellation Mon, shines at apparent magnitude 6.94 and has spectral type B0IV.

Its spectrum reads B0IV — 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 HD 47417 in the constellation Mon. At apparent magnitude 6.94, it is an easy target for binoculars.

Like any astronomical target, HD 47417 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 47417 is an uncommon star

HD 47417 scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 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 Intrinsically luminous (Mv < −2) — 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.