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Uncommon variable star 23 EP

HD 210548

RA 335.5105° · Dec -84.6662° · star

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Score breakdown

· 5 badges
23 pts · Uncommon
Uncommon 34 pts → Rare
  • Giant star +6
  • Variable star +5
  • Cool red M-type star +5
  • Gently variable +4
  • A named variable star +3
Total score 23

11 more points to reach Rare.

Badges

  • Variable star · +5
  • Cool red M-type star · +5
  • Giant star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M7III — 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 8.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Octans.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around August — that's when to go looking.

Could we get there?

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

Properties

absmag
1.74
bv
1.276
constellation
Oct
dist ly
815.39
luminosity
17.5388
mag
8.73
name
HD 210548
spect
M7III
var amplitude
0.34
var designation
BW
var max
8.577
var min
8.917

About HD 210548

HD 210548 is an uncommon variable star. It lies about 815.4 light-years from Earth, sits in the constellation Oct, shines at apparent magnitude 8.73 and has spectral type M7III.

Its spectrum reads M7III — 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 210548 in the constellation Oct. At apparent magnitude 8.73, it is an easy target for binoculars.

Like any astronomical target, HD 210548 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 210548 is an uncommon variable star

HD 210548 scores 23 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Cool red M-type star, Giant star, Gently 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.