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Common variable star 20 EP

HD 19902

RA 48.2616° · Dec 32.8964° · star

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Score breakdown

· 4 badges
20 pts · Common
Common 22 pts → Uncommon
  • Sun-like G-type star +8
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • Sun-like G-type star · +8
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads G5 — a G-type star: the very same spectral class as our own 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 8.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Perseus.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • 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. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 2.3 million years at Voyager 1's speed (17 km/s).

Properties

absmag
5.165
bv
0.732
constellation
Per
dist ly
128.9663
luminosity
0.7482
mag
8.15
name
HD 19902
spect
G5
var amplitude
0.05
var designation
V683
var max
8.128
var min
8.178

About HD 19902

HD 19902 is a common variable star. It lies about 129 light-years from Earth, sits in the constellation Per, shines at apparent magnitude 8.15 and has spectral type G5.

Its spectrum reads G5 — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for HD 19902 in the constellation Per. At apparent magnitude 8.15, it is an easy target for binoculars.

Like any astronomical target, HD 19902 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 19902 is a common variable star

HD 19902 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Sun-like G-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.