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Common star 16 EP

HD 202939

RA 319.9031° · Dec -16.7771° · star

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Score breakdown

· 4 badges
16 pts · Common
Common 22 pts → Uncommon
  • White A-type star +5
  • Subgiant (leaving the main sequence) +5
  • Star +3
  • On the zodiac +3
Total score 16

6 more points to reach Uncommon.

Badges

  • Star · +3
  • On the zodiac · +3
  • White A-type star · +5
  • Subgiant (leaving the main sequence) · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads A0/A1IV — 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.

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 9.1 you'll want a small backyard telescope, over in Capricornus.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around August — 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. ≈ 14.1 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 1.3 million years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
2.128
bv
0.049
constellation
Cap
dist ly
801.3659
luminosity
12.2687
mag
9.08
name
HD 202939
spect
A0/A1IV

About HD 202939

HD 202939 is a common star. It lies about 801.4 light-years from Earth, sits in the constellation Cap, shines at apparent magnitude 9.08 and has spectral type A0/A1IV.

Its spectrum reads A0/A1IV — 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 HD 202939 in the constellation Cap. At apparent magnitude 9.08, a small backyard telescope will bring it into view.

Like any astronomical target, HD 202939 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 202939 is a common star

HD 202939 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, On the zodiac, White A-type star and Subgiant (leaving the main sequence) — 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.