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Uncommon variable star 29 EP

HD 122453

RA 211.0869° · Dec -65.4160° · star

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Score breakdown

· 6 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Subgiant (leaving the main sequence) +5
  • Gently variable +4
  • A named variable star +3
Total score 29

5 more points to reach Rare.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9IV/V — 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 a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.
  • 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 7.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Circinus.
  • 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 April — that's when to go looking.

Could we get there?

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

Properties

absmag
-0.159
bv
0.063
constellation
Cir
dist ly
1358.9834
luminosity
100.8324
mag
7.94
name
HD 122453
spect
B9IV/V
var amplitude
0.12
var designation
CE
var max
7.915
var min
8.035

About HD 122453

HD 122453 is an uncommon variable star. It lies about 1,359 light-years from Earth, sits in the constellation Cir, shines at apparent magnitude 7.94 and has spectral type B9IV/V.

Its spectrum reads B9IV/V — 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 HD 122453 in the constellation Cir. At apparent magnitude 7.94, it is an easy target for binoculars.

Like any astronomical target, HD 122453 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 122453 is an uncommon variable star

HD 122453 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Distant (over 1,000 light-years), Hot blue B-type star, Subgiant (leaving the main sequence), 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.