← Back to dex
Epic variable star 52 EP

39Eps Cap

RA 324.2701° · Dec -19.4660° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 10 badges
52 pts · Epic
Epic 78 pts → Anomaly
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
  • Main-sequence star +2
Total score 52

26 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Naked-eye visible · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3V:p — 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 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 4.5 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. Impossible with our current technology — and the next millennium of it.

Properties

absmag
-3.04
bv
-0.18
constellation
Cap
dist ly
1055.5211
luminosity
1432.1879
mag
4.51
name
39Eps Cap
spect
B3V:p
var amplitude
0.16
var designation
Eps
var max
4.465
var min
4.625

About 39Eps Cap

39Eps Cap is an epic variable star. It lies about 1,055.5 light-years from Earth, sits in the constellation Cap, shines at apparent magnitude 4.51 and has spectral type B3V:p.

Its spectrum reads B3V:p — 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 39Eps Cap in the constellation Cap. At apparent magnitude 4.51, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 39Eps 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 39Eps Cap is an epic variable star

39Eps Cap scores 52 points on Spacedle's rarity scale, which places it in the epic tier. Another 26 points would lift it into a rarer tier.

That score comes from 10 science badges — Variable star, Distant (over 1,000 light-years), Naked-eye visible, On the zodiac, Hot blue B-type star, Main-sequence star, Blue-white star and Intrinsically luminous (Mv < −2) — 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.