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Uncommon star 23 EP

HR 3721

RA 139.3651° · Dec -74.7346° · star

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Score breakdown

· 5 badges
23 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • White A-type star +5
  • Blue-white star +5
  • Star +3
  • Main-sequence star +2
Total score 23

11 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • White A-type star · +5
  • Main-sequence star · +2
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads A0V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.

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 5.9 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. ≈ 4.7 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.292
bv
-0.024
constellation
Car
dist ly
267.3409
luminosity
26.4972
mag
5.86
name
HR 3721
spect
A0V

About HR 3721

HR 3721 is an uncommon star. It lies about 267.3 light-years from Earth, sits in the constellation Car, shines at apparent magnitude 5.86 and has spectral type A0V.

Its spectrum reads A0V — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HR 3721 in the constellation Car. At apparent magnitude 5.86, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 3721 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 3721 is an uncommon star

HR 3721 scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Naked-eye visible, White A-type star, Main-sequence star 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.