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Rare star 49 EP

HR 1861

RA 83.1723° · Dec -1.5918° · star

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Score breakdown

· 8 badges
49 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Distant (over 1,000 light-years) +6
  • In Orion's hunting ground +6
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
Total score 49

1 more point to reach Epic.

Badges

  • Star · +3
  • Distant (over 1,000 light-years) · +6
  • Naked-eye visible · +8
  • In Orion's hunting ground · +6
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1IV — 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 5.3 you can see it with your own eyes from a dark site, over in Orion.
  • 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. ≈ 27.4 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-3.059
bv
-0.188
constellation
Ori
dist ly
1560.555
luminosity
1457.4713
mag
5.34
name
HR 1861
spect
B1IV

About HR 1861

HR 1861 is a rare star. It lies about 1,560.6 light-years from Earth, sits in the constellation Ori, shines at apparent magnitude 5.34 and has spectral type B1IV.

Its spectrum reads B1IV — 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 1861 in the constellation Ori. At apparent magnitude 5.34, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 1861 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 1861 is a rare star

HR 1861 scores 49 points on Spacedle's rarity scale, which places it in the rare tier. Another 1 point would lift it into a rarer tier.

That score comes from 8 science badges — Star, Distant (over 1,000 light-years), Naked-eye visible, In Orion's hunting ground, Hot blue B-type star, Subgiant (leaving the main sequence), Blue-white star 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.