← Back to dex
Rare variable star 44 EP

HR 4250

RA 163.1285° · Dec -57.2404° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 6 badges
44 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 44

6 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9Ia — 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 luminous supergiant — among the largest and rarest stars in the galaxy.
  • 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.

Find it in the sky

  • How to spot it. At magnitude 5.3 you can see it with your own eyes from a dark site, over in Carina.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out brilliant white (B−V 0.1) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

Properties

absmag
-14.74
bv
0.13
constellation
Car
luminosity
68548822.6453
mag
5.26
name
HR 4250
spect
B9Ia
var amplitude
0.08
var designation
V524
var max
5.226
var min
5.306

About HR 4250

HR 4250 is a rare variable star. It sits in the constellation Car, shines at apparent magnitude 5.26 and has spectral type B9Ia.

Its spectrum reads B9Ia — 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 HR 4250 in the constellation Car. At apparent magnitude 5.26, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 4250 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 HR 4250 is a rare variable star

HR 4250 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Naked-eye visible, Hot blue B-type star, Supergiant, 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.