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Uncommon star 26 EP

HD 66306

RA 120.4880° · Dec -27.2148° · star

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Score breakdown

· 4 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Bright giant +12
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
Total score 26

8 more points to reach Rare.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Bright giant · +12
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B7II — 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.
  • Where it is in life. It is a bright giant, well on its way to the largest stars there are.

Find it in the sky

  • How to spot it. At magnitude 6.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Puppis.
  • 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 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) — 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 10650 K, against the Sun's 5778 K.

Properties

absmag
-13.18
bv
-0.04
constellation
Pup
luminosity
16292960.3264
mag
6.82
name
HD 66306
spect
B7II

About HD 66306

HD 66306 is an uncommon star. It sits in the constellation Pup, shines at apparent magnitude 6.82 and has spectral type B7II.

Its spectrum reads B7II — 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 66306 in the constellation Pup. At apparent magnitude 6.82, it is an easy target for binoculars.

Like any astronomical target, HD 66306 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 66306 is an uncommon star

HD 66306 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 4 science badges — Star, Hot blue B-type star, Bright giant 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.