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Rare variable star 49 EP

HD 218997

RA 347.9196° · Dec 59.6997° · star

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Score breakdown

· 7 badges
49 pts · Rare
Rare 50 pts → Epic
  • Dramatic variable (over 2 magnitudes) +20
  • Distant (over 1,000 light-years) +6
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • Never sets (northern circumpolar) +4
  • A named variable star +3
Total score 49

1 more point to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Cool red M-type star · +5
  • Red dwarf · +6
  • Dramatic variable (over 2 magnitudes) · +20
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M5e-M8.5e — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • 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 8.8 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.

Getting there

  • Aboard Voyager 1. ≈ 26.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.412
bv
1.289
constellation
Cas
dist ly
1524.0934
luminosity
59.5937
mag
8.76
name
HD 218997
spect
M5e-M8.5e
var amplitude
3.15
var designation
V
var max
7.386
var min
10.536

About HD 218997

HD 218997 is a rare variable star. It lies about 1,524.1 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 8.76 and has spectral type M5e-M8.5e.

Its spectrum reads M5e-M8.5e — 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 218997 in the constellation Cas. At apparent magnitude 8.76, it is an easy target for binoculars.

Like any astronomical target, HD 218997 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 218997 is a rare variable star

HD 218997 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 7 science badges — Variable star, Distant (over 1,000 light-years), Never sets (northern circumpolar), Cool red M-type star, Red dwarf, Dramatic variable (over 2 magnitudes) 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.