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Rare variable star 49 EP

28Eta Ori

RA 81.1192° · Dec -2.3971° · star

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Score breakdown

· 9 badges
49 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • In Orion's hunting ground +6
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • Gently variable +4
  • A named variable star +3
  • Main-sequence star +2
Total score 49

1 more point to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • In Orion's hunting ground · +6
  • 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 B1V + B2 — 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 3.4 you can see it with your own eyes from a dark site, over in Orion.
  • 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 December — that's when to go looking.

Could we get there?

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

Properties

absmag
-4.031
bv
-0.24
constellation
Ori
dist ly
976.515
luminosity
3567.7959
mag
3.35
name
28Eta Ori
spect
B1V + B2
var amplitude
0.27
var designation
Eta
var max
3.319
var min
3.589

About 28Eta Ori

28Eta Ori is a rare variable star. It lies about 976.5 light-years from Earth, sits in the constellation Ori, shines at apparent magnitude 3.35 and has spectral type B1V + B2.

Its spectrum reads B1V + B2 — 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 28Eta Ori in the constellation Ori. At apparent magnitude 3.35, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 28Eta Ori 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 28Eta Ori is a rare variable star

28Eta Ori scores 49 points on Spacedle's rarity scale, which places it in the rare tier. Another 1 point would lift it into a rarer tier.

That score comes from 9 science badges — Variable star, Naked-eye visible, In Orion's hunting ground, Hot blue B-type star, Main-sequence 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.