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Uncommon variable star 26 EP

HD 213985

RA 338.8647° · Dec -17.2575° · star

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Score breakdown

· 6 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Giant star +6
  • Variable star +5
  • White A-type star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
Total score 26

8 more points to reach Rare.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • White A-type star · +5
  • Giant star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 2.6 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 A0III — 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.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
  • 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 8.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Aquarius.
  • 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 August — 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 0.2) — hotter and whiter than the Sun, the colour of Sirius or Vega.

Properties

absmag
-11.19
bv
0.151
constellation
Aqr
luminosity
2606153.55
mag
8.81
name
HD 213985
spect
A0III
var amplitude
0.31
var designation
HM
var max
8.739
var min
9.049

About HD 213985

HD 213985 is an uncommon variable star. It sits in the constellation Aqr, shines at apparent magnitude 8.81 and has spectral type A0III.

Its spectrum reads A0III — 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 213985 in the constellation Aqr. At apparent magnitude 8.81, it is an easy target for binoculars.

Like any astronomical target, HD 213985 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 213985 is an uncommon variable star

HD 213985 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, On the zodiac, White A-type star, Giant 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.