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Common variable star 21 EP

HD 276861

RA 72.4498° · Dec 42.2897° · star

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Score breakdown

· 4 badges
21 pts · Common
Common 22 pts → Uncommon
  • Strongly variable +10
  • Variable star +5
  • Yellow-white F-type star +3
  • A named variable star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Variable star · +5
  • Yellow-white F-type star · +3
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 2.4 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 F8 — 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.

Find it in the sky

  • How to spot it. At magnitude 8.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Perseus.
  • 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 December — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out orange (B−V 0.9) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
  • 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
-11.14
bv
0.901
constellation
Per
luminosity
2488857.3183
mag
8.86
name
HD 276861
spect
F8
var amplitude
0.87
var designation
SV
var max
8.464
var min
9.334

About HD 276861

HD 276861 is a common variable star. It sits in the constellation Per, shines at apparent magnitude 8.86 and has spectral type F8.

Its spectrum reads F8 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 276861 in the constellation Per. At apparent magnitude 8.86, it is an easy target for binoculars.

Like any astronomical target, HD 276861 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 276861 is a common variable star

HD 276861 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Yellow-white F-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.