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Epic variable star 69 EP

HR 65

RA 4.4294° · Dec 51.4331° · star

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Score breakdown

· 9 badges
69 pts · Epic
Epic 78 pts → Anomaly
  • Blazing O-type star +26
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • Giant star +6
  • Variable star +5
  • Blue-white star +5
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
Total score 69

9 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Blazing O-type star · +26
  • Giant star · +6
  • 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 O9IIInn — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.
  • 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 6.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cassiopeia.
  • 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 September — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Properties

absmag
-3.222
bv
-0.151
constellation
Cas
dist ly
2398.2058
luminosity
1693.5577
mag
6.11
name
HR 65
spect
O9IIInn
var amplitude
0.18
var designation
AO
var max
6.045
var min
6.225

About HR 65

HR 65 is an epic variable star. It lies about 2,398.2 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 6.11 and has spectral type O9IIInn.

Its spectrum reads O9IIInn — an O-type star — the hottest, rarest main class there is. Fewer than one star in a million is an O, and none of them lasts long.

How to see it

Look for HR 65 in the constellation Cas. At apparent magnitude 6.11, it is an easy target for binoculars.

Like any astronomical target, HR 65 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 HR 65 is an epic variable star

HR 65 scores 69 points on Spacedle's rarity scale, which places it in the epic tier. Another 9 points would lift it into a rarer tier.

That score comes from 9 science badges — Variable star, Distant (over 1,000 light-years), Never sets (northern circumpolar), Blazing O-type star, Giant star, Blue-white star, Intrinsically luminous (Mv < −2) and Gently variable — 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.