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Rare nebula 38 EP

Blue Planetary

RA 177.5748° · Dec -57.1823° · openngc

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Score breakdown

· 4 badges
38 pts · Rare
Rare 50 pts → Epic
  • Planetary nebula (a dying star's shell) +12
  • Coming towards us +10
  • Nebula +8
  • Has a proper name +8
Total score 38

12 more points to reach Epic.

Badges

  • Nebula · +8
  • Has a proper name · +8
  • Planetary nebula (a dying star's shell) · +12
  • Coming towards us · +10

Trivia

What it actually is

  • What it actually is. A planetary nebula: the shed outer atmosphere of a dying Sun-like star, lit from within by the naked stellar core left behind.

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 Centaurus.
  • 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 March — that's when to go looking.

Its true colour

  • Its true colour. Its teal-green comes from doubly-ionised oxygen at 501 nanometres, and its red from hydrogen at 656 — colours no ordinary object on Earth produces.

What's in a name

  • A misleading name. 'Planetary nebula' is a 240-year-old mistake. William Herschel coined it in the 1780s because these round greenish discs resembled the planet Uranus he had just discovered. There are no planets involved whatsoever.
  • Named. Notable enough to have earned a proper name, not just a catalogue number.

How we came to know it

  • The New General Catalogue. Its NGC number comes from J. L. E. Dreyer's 1888 catalogue, itself built on decades of sky sweeps by William Herschel and his sister Caroline.

Properties

constellation
Cen
dso type
PN
mag
8.1
name
Blue Planetary
named
yes
radial velocity kms
-16
size arcmin
0.32

Nearby objects

About Blue Planetary

Blue Planetary is a rare nebula. It sits in the constellation Cen and shines at apparent magnitude 8.1.

A planetary nebula: the shed outer atmosphere of a dying Sun-like star, lit from within by the naked stellar core left behind.

How to see it

Look for Blue Planetary in the constellation Cen. At apparent magnitude 8.1, it is an easy target for binoculars.

Like any astronomical target, Blue Planetary 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 Blue Planetary is a rare nebula

Blue Planetary scores 38 points on Spacedle's rarity scale, which places it in the rare tier. Another 12 points would lift it into a rarer tier.

That score comes from 4 science badges — Nebula, Has a proper name, Planetary nebula (a dying star's shell) and Coming towards us — 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.