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Rare variable star 43 EP

HD 39983

RA 89.2808° · Dec 22.8389° · star

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Score breakdown

· 7 badges
43 pts · Rare
Rare 50 pts → Epic
  • Strongly variable +10
  • Deep red star +8
  • In Orion's hunting ground +6
  • Giant star +6
  • Variable star +5
  • Cool red M-type star +5
  • A named variable star +3
Total score 43

7 more points to reach Epic.

Badges

  • Variable star · +5
  • In Orion's hunting ground · +6
  • Cool red M-type star · +5
  • Giant star · +6
  • Deep red star · +8
  • Strongly variable · +10
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M5IIIvar — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • 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 8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Orion.
  • 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 December — that's when to go looking.

Could we get there?

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

Properties

absmag
1.374
bv
1.482
constellation
Ori
dist ly
689.5476
luminosity
24.5697
mag
8
name
HD 39983
spect
M5IIIvar
var amplitude
0.9
var designation
BQ
var max
7.205
var min
8.105

About HD 39983

HD 39983 is a rare variable star. It lies about 689.5 light-years from Earth, sits in the constellation Ori, shines at apparent magnitude 8 and has spectral type M5IIIvar.

Its spectrum reads M5IIIvar — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.

How to see it

Look for HD 39983 in the constellation Ori. At apparent magnitude 8, it is an easy target for binoculars.

Like any astronomical target, HD 39983 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 HD 39983 is a rare variable star

HD 39983 scores 43 points on Spacedle's rarity scale, which places it in the rare tier. Another 7 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, In Orion's hunting ground, Cool red M-type star, Giant star, Deep red star, Strongly variable 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.