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The Ghost of Jupiter

Planetary Nebula
aka "The Eye", NGC 3242, PN G261.0+32.0, PK 261+32.1, ARO 4, ESO 568-5
RA: 10h24m46.1s, Dec: -18°38'32" (2000) in Hydra
Magnitude: 8.60
Size: 25"

Mean Surface Br. 15.3 Mag/arc-secē

Distance: 2800 ly

Minimum requirements to detect: any telescope under urban skies

The Ghost of Jupiter is one of the finest planetary nebulae for any size telescope, and one of the most observed non-Messier's.  This object was discovered by William Herschel in 1785.

In a small telescope it appears as small, oval disk that bears a close resemblance to Jupiter (hence the name).  It was H. Smyth who first noted this resemblance.  Like most bright planetary nebulae, the Ghost appears pale blue or green to the eyes of most observers.

In my 6-inch it appears as an oblong disc of unusually high surface brightness and sharp, well defined edges.

For those with access to larger-aperture instruments, NGC 3242 has an abundance of delightful detail in store.  Burnham wrote, "There is a bright, strongly elliptical inner ring which strikingly resembles the outline of a human eye; this feature measures 26" x 16" and is oriented southeast to northwest."  The central star is about 12th magnitude and sits right at the center of the elongated inner ring, completing the "Eye",  another apt name for this wonderful object.  The HST image at the top of the page shows this inner ring quite well.  Of course, don't expect this level of detail in the eyepiece!

I observed NGC 3242 in my 18-inch Dob in February 2000. Here are my notes from that session:

At 425x The Ghost took on an appearance quite similar to that of NGC 1535 (Cleopatra's Eye) and NGC 2392 (The Eskimo).  Once again I found myself looking at a large oval with a bright, elongated ring surrounding the central star.  I'm always struck by how sharp the outer edges of this one are.  The surface brightness of this planetary is higher than the other two; the inner-ring detail was not quite as obvious as that of NGC 1535, but much more easily visible than that of the Eskimo.  This is one of those objects worth returning to again and again, regardless of the instrument.
According to David Knisely The Ghost is shows a large improvement using UHC and OIII filters.  For the UHC he finds "much higher contrast with faint circular outer halo-like shell beyond the two inner shells now visible."  And for the OIII,  "much darker background but the two inner shells really blaze out."  

This image from the DSS shows a 20' x' 20' field. North is down and east is to the right.

The view in a 6-inch at 50x. North is down, east is right.

Millennium Star Atlas Vol II Chart 851
Sky Atlas 2000 Chart 20
Uranometria 2000 Vol II Chart 325
Uranometria 2nd Ed. Chart 151
Herald-Bobroff Astroatlas B-06 C-57