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Rare variable star 48 EP

Kap Sco

RA 265.6220° · Dec -39.0300° · star

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Score breakdown

· 9 badges
48 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Giant star +6
  • Variable star +5
  • Blue-white star +5
  • On the zodiac +3
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 48

2 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Giant star · +6
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1.5III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
  • 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 2.4 you can see it with your own eyes from a dark site, over in Scorpius.
  • 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 June — that's when to go looking.

Could we get there?

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

Properties

absmag
-3.463
bv
-0.171
constellation
Sco
dist ly
483.1939
luminosity
2114.4626
mag
2.39
name
Kap Sco
spect
B1.5III
var amplitude
0.02
var designation
Kap
var max
2.384
var min
2.404

About Kap Sco

Kap Sco is a rare variable star. It lies about 483.2 light-years from Earth, sits in the constellation Sco, shines at apparent magnitude 2.39 and has spectral type B1.5III.

Its spectrum reads B1.5III — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for Kap Sco in the constellation Sco. At apparent magnitude 2.39, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Kap Sco 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 Kap Sco is a rare variable star

Kap Sco scores 48 points on Spacedle's rarity scale, which places it in the rare tier. Another 2 points would lift it into a rarer tier.

That score comes from 9 science badges — Variable star, Naked-eye visible, On the zodiac, Hot blue B-type star, Giant star, Blue-white star, Intrinsically luminous (Mv < −2) and Barely variable (under 0.05 mag) — 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.