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Common variable star 20 EP

HD 103720

RA 179.1716° · Dec -2.7790° · star

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Score breakdown

· 6 badges
20 pts · Common
Common 22 pts → Uncommon
  • Variable star +5
  • Gently variable +4
  • On the zodiac +3
  • Orange K-type star +3
  • A named variable star +3
  • Main-sequence star +2
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • Orange K-type star · +3
  • Main-sequence star · +2
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads K3V — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.
  • 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 9.5 you'll want a small backyard telescope, over in Virgo.
  • 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 March — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

absmag
6.406
bv
0.945
constellation
Vir
dist ly
135.6157
luminosity
0.2386
mag
9.5
name
HD 103720
spect
K3V
var amplitude
0.08
var designation
PR
var max
9.452
var min
9.532

About HD 103720

HD 103720 is a common variable star. It lies about 135.6 light-years from Earth, sits in the constellation Vir, shines at apparent magnitude 9.5 and has spectral type K3V.

Its spectrum reads K3V — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 103720 in the constellation Vir. At apparent magnitude 9.5, a small backyard telescope will bring it into view.

Like any astronomical target, HD 103720 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 103720 is a common variable star

HD 103720 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 6 science badges — Variable star, On the zodiac, Orange K-type star, Main-sequence 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.