← Back to dex
Common variable star 16 EP

HD 224638

RA 359.8960° · Dec -1.8499° · star

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

Computing the sky for your location…

Score breakdown

· 5 badges
16 pts · Common
Common 22 pts → Uncommon
  • Variable star +5
  • On the zodiac +3
  • Yellow-white F-type star +3
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 16

6 more points to reach Uncommon.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • Yellow-white F-type star · +3
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads F0 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • 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 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Pisces.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around September — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
2.797
bv
0.342
constellation
Psc
dist ly
283.1217
luminosity
6.6252
mag
7.49
name
HD 224638
spect
F0
var amplitude
0.04
var designation
BT
var max
7.466
var min
7.506

About HD 224638

HD 224638 is a common variable star. It lies about 283.1 light-years from Earth, sits in the constellation Psc, shines at apparent magnitude 7.49 and has spectral type F0.

Its spectrum reads F0 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 224638 in the constellation Psc. At apparent magnitude 7.49, it is an easy target for binoculars.

Like any astronomical target, HD 224638 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 224638 is a common variable star

HD 224638 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, On the zodiac, Yellow-white F-type star, Barely variable (under 0.05 mag) 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.