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Rare variable star 40 EP

HD 19243

RA 47.2258° · Dec 62.3846° · star

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Score breakdown

· 8 badges
40 pts · Rare
Rare 50 pts → Epic
  • Intrinsically luminous (Mv < −2) +10
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Never sets (northern circumpolar) +4
  • Gently variable +4
  • A named variable star +3
  • Main-sequence star +2
Total score 40

10 more points to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Intrinsically luminous (Mv < −2) · +10
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1V:e — 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 on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • 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 6.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cassiopeia.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • 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
-3.028
bv
0.231
constellation
Cas
dist ly
2588.5397
luminosity
1416.4459
mag
6.47
name
HD 19243
spect
B1V:e
var amplitude
0.1
var designation
V801
var max
6.414
var min
6.514

About HD 19243

HD 19243 is a rare variable star. It lies about 2,588.5 light-years from Earth, sits in the constellation Cas, shines at apparent magnitude 6.47 and has spectral type B1V:e.

Its spectrum reads B1V:e — 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 19243 in the constellation Cas. At apparent magnitude 6.47, it is an easy target for binoculars.

Like any astronomical target, HD 19243 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 19243 is a rare variable star

HD 19243 scores 40 points on Spacedle's rarity scale, which places it in the rare tier. Another 10 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Distant (over 1,000 light-years), Never sets (northern circumpolar), Hot blue B-type star, Main-sequence star, Intrinsically luminous (Mv < −2), 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.