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Common variable star 21 EP

HD 20940

RA 50.6580° · Dec -0.5285° · star

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Score breakdown

· 5 badges
21 pts · Common
Common 22 pts → Uncommon
  • Distant (over 1,000 light-years) +6
  • Variable star +5
  • Gently variable +4
  • Yellow-white F-type star +3
  • A named variable star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Yellow-white F-type star · +3
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads F8 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

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 9.7 you'll want a small backyard telescope, over in Cetus.
  • 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 November — 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. ≈ 20.5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
1.926
bv
0.575
constellation
Cet
dist ly
1164.843
luminosity
14.7775
mag
9.69
name
HD 20940
spect
F8
var amplitude
0.18
var designation
EM
var max
9.653
var min
9.833

About HD 20940

HD 20940 is a common variable star. It lies about 1,164.8 light-years from Earth, sits in the constellation Cet, shines at apparent magnitude 9.69 and has spectral type F8.

Its spectrum reads F8 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 20940 in the constellation Cet. At apparent magnitude 9.69, a small backyard telescope will bring it into view.

Like any astronomical target, HD 20940 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 20940 is a common variable star

HD 20940 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Distant (over 1,000 light-years), Yellow-white F-type star, Gently variable and A named variable 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.