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Common star 17 EP

HD 69868

RA 124.9319° · Dec 20.9181° · star

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Score breakdown

· 4 badges
17 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
  • On the zodiac +3
Total score 17

5 more points to reach Uncommon.

Badges

  • Star · +3
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Blue-white star · +5

Trivia

Hard to believe

  • True brightness. It pours out about 4.9 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 B9 — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

Find it in the sky

  • How to spot it. At magnitude 8.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Cancer.
  • 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 blue-white (B−V -0.1) — the hallmark of a surface far hotter than the Sun's.
  • 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.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 11060 K, against the Sun's 5778 K.

Properties

absmag
-11.89
bv
-0.068
constellation
Cnc
luminosity
4965923.2145
mag
8.11
name
HD 69868
spect
B9

Nearby objects

About HD 69868

HD 69868 is a common star. It sits in the constellation Cnc, shines at apparent magnitude 8.11 and has spectral type B9.

Its spectrum reads B9 — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 69868 in the constellation Cnc. At apparent magnitude 8.11, it is an easy target for binoculars.

Like any astronomical target, HD 69868 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 69868 is a common star

HD 69868 scores 17 points on Spacedle's rarity scale, which places it in the common tier. Another 5 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, On the zodiac, Hot blue B-type star and Blue-white 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.