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Uncommon variable star 33 EP

HD 237090

RA 48.7955° · Dec 59.9119° · star

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Score breakdown

· 7 badges
33 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
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
Total score 33

1 more point to reach Rare.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • 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 B0.5IV:nn — 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 9.1 you'll want a small backyard telescope, 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 November — that's when to go looking.

Could we get there?

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

Properties

absmag
-0.743
bv
0.534
constellation
Cas
dist ly
3019.9629
luminosity
172.6633
mag
9.09
name
HD 237090
spect
B0.5IV:nn
var amplitude
0.16
var designation
V803
var max
9.006
var min
9.166

About HD 237090

HD 237090 is an uncommon variable star. It lies about 3,020 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 9.09 and has spectral type B0.5IV:nn.

Its spectrum reads B0.5IV:nn — 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 237090 in the constellation Cas. At apparent magnitude 9.09, a small backyard telescope will bring it into view.

Like any astronomical target, HD 237090 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 237090 is an uncommon variable star

HD 237090 scores 33 points on Spacedle's rarity scale, which places it in the uncommon 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), 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.