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Common star 15 EP

HD 242018

RA 78.7842° · Dec 6.4412° · star

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Score breakdown

· 3 badges
15 pts · Common
Common 22 pts → Uncommon
  • In Orion's hunting ground +6
  • Hot blue B-type star +6
  • Star +3
Total score 15

7 more points to reach Uncommon.

Badges

  • Star · +3
  • In Orion's hunting ground · +6
  • Hot blue B-type star · +6

Trivia

Hard to believe

  • True brightness. It pours out about 580.8 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 B8 — 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 10.4 you'll want a small backyard telescope, over in Orion.
  • 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 December — 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) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • 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 9810 K, against the Sun's 5778 K.

Properties

absmag
-9.58
bv
0.026
constellation
Ori
luminosity
591561.6342
mag
10.42
name
HD 242018
spect
B8

About HD 242018

HD 242018 is a common star. It sits in the constellation Ori, shines at apparent magnitude 10.42 and has spectral type B8.

Its spectrum reads B8 — 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 242018 in the constellation Ori. At apparent magnitude 10.42, a small backyard telescope will bring it into view.

Like any astronomical target, HD 242018 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 242018 is a common star

HD 242018 scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 7 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, In Orion's hunting ground and Hot blue B-type 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.