← Back to dex
Common variable star 20 EP

HD 209596

RA 330.8659° · Dec 45.5686° · star

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

Computing the sky for your location…

Score breakdown

· 4 badges
20 pts · Common
Common 22 pts → Uncommon
  • Deep red star +8
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • Deep red star · +8
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 816.6 thousand 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 N0 — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.
  • 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 10.1 you'll want a small backyard telescope, over in Lacerta.
  • 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 August — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 2.4) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 2800 K, against the Sun's 5778 K.

Properties

absmag
-9.95
bv
2.4
constellation
Lac
luminosity
831763.7711
mag
10.05
name
HD 209596
spect
N0
var amplitude
0.26
var designation
V378
var max
9.941
var min
10.201

About HD 209596

HD 209596 is a common variable star. It sits in the constellation Lac, shines at apparent magnitude 10.05 and has spectral type N0.

Its spectrum reads N0 — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.

How to see it

Look for HD 209596 in the constellation Lac. At apparent magnitude 10.05, a small backyard telescope will bring it into view.

Like any astronomical target, HD 209596 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 209596 is a common variable star

HD 209596 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Deep red star, 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.