← Back to dex
Uncommon variable star 23 EP

HD 67390

RA 122.3990° · Dec 44.4716° · star

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

Computing the sky for your location…

Score breakdown

· 4 badges
23 pts · Uncommon
Uncommon 34 pts → Rare
  • Strongly variable +10
  • Variable star +5
  • White A-type star +5
  • A named variable star +3
Total score 23

11 more points to reach Rare.

Badges

  • Variable star · +5
  • White A-type star · +5
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1.4 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

  • Spectral class. Its spectrum reads A9 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • 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 9.4 you'll want a small backyard telescope, over in Lynx.
  • 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 January — 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 0.3) — 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
-10.56
bv
0.277
constellation
Lyn
luminosity
1458814.2603
mag
9.44
name
HD 67390
spect
A9
var amplitude
0.53
var designation
SZ
var max
9.095
var min
9.625

About HD 67390

HD 67390 is an uncommon variable star. It sits in the constellation Lyn, shines at apparent magnitude 9.44 and has spectral type A9.

Its spectrum reads A9 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 67390 in the constellation Lyn. At apparent magnitude 9.44, a small backyard telescope will bring it into view.

Like any astronomical target, HD 67390 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 67390 is an uncommon variable star

HD 67390 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 4 science badges — Variable star, White A-type star, Strongly 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.