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Uncommon variable star 31 EP

42 Cap

RA 325.3869° · Dec -14.0476° · star

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Score breakdown

· 7 badges
31 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Sun-like G-type star +8
  • Variable star +5
  • On the zodiac +3
  • A named variable star +3
  • Main-sequence star +2
  • Barely variable (under 0.05 mag) +2
Total score 31

3 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • On the zodiac · +3
  • Sun-like G-type star · +8
  • Main-sequence star · +2
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads G2V — a G-type star: the very same spectral class as our own Sun.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • 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 5.2 you can see it with your own eyes from a dark site, 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.

Properties

absmag
2.552
bv
0.672
constellation
Cap
dist ly
108.3934
luminosity
8.3023
mag
5.16
name
42 Cap
spect
G2V
var amplitude
0.03
var designation
BY
var max
5.147
var min
5.177

About 42 Cap

42 Cap is an uncommon variable star. It lies about 108.4 light-years from Earth, sits in the constellation Cap, shines at apparent magnitude 5.16 and has spectral type G2V.

Its spectrum reads G2V — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for 42 Cap in the constellation Cap. At apparent magnitude 5.16, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 42 Cap 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 42 Cap is an uncommon variable star

42 Cap scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 3 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Naked-eye visible, On the zodiac, Sun-like G-type star, Main-sequence star, Barely variable (under 0.05 mag) 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.