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Rare variable star 45 EP

Eps Cen

RA 204.9719° · Dec -53.4664° · star

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Score breakdown

· 8 badges
45 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
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 45

5 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • 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 B1III — 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 2.3 you can see it with your own eyes from a dark site, over in Centaurus.
  • 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 April — that's when to go looking.

Could we get there?

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

Properties

absmag
-3.297
bv
-0.171
constellation
Cen
dist ly
427.4653
luminosity
1814.6798
mag
2.29
name
Eps Cen
spect
B1III
var amplitude
0.02
var designation
Eps
var max
2.281
var min
2.301

About Eps Cen

Eps Cen is a rare variable star. It lies about 427.5 light-years from Earth, sits in the constellation Cen, shines at apparent magnitude 2.29 and has spectral type B1III.

Its spectrum reads B1III — 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 Eps Cen in the constellation Cen. At apparent magnitude 2.29, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Eps Cen 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 Eps Cen is a rare variable star

Eps Cen scores 45 points on Spacedle's rarity scale, which places it in the rare tier. Another 5 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Naked-eye visible, Hot blue B-type star, Giant star, Blue-white star, Intrinsically luminous (Mv < −2), 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.