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Rare star 37 EP

HR 3663

RA 137.8198° · Dec -62.3170° · star

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Score breakdown

· 6 badges
37 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
Total score 37

13 more points to reach Epic.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • 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 B3IV — 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 4 you can see it with your own eyes from a dark site, over in Carina.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around February — 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. ≈ 9.5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-2.146
bv
-0.18
constellation
Car
dist ly
542.689
luminosity
628.6371
mag
3.96
name
HR 3663
spect
B3IV

About HR 3663

HR 3663 is a rare star. It lies about 542.7 light-years from Earth, sits in the constellation Car, shines at apparent magnitude 3.96 and has spectral type B3IV.

Its spectrum reads B3IV — 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 3663 in the constellation Car. At apparent magnitude 3.96, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 3663 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 3663 is a rare star

HR 3663 scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, 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.