NGC 3242

Right Ascension	10 : 24.8 (h:m)
Declination	-18 : 38 (deg:m)
Distance	2.5 (kly)
Visual brightness	7.7 (mag)
Apparent Dimension	20.8 (arc min); halo

William Herschel discovered this planetary nebula on February 7, 1785, and cataloged it as H IV.27. John Herschel observed it from the Cape of Good Hope, South Africa, in the 1830s, and numbered it as h 3248, and included it in the 1864 General Catalogue as GC 2102; this became NGC 3242 in J.L.E. Dreyer's New General Catalogue of 1888.

This planetary nebula consists of a small dense nebula of about 16" x 26" in diameter, surrounded by a fainter envelop measuring about 40 x 35 arc seconds. This central nebula is embedded in a much larger faint halo, measuring 1250" or about 20.8 arc minutes in diameter. The bright inner nebula is described as looking like an eye by Burnham, and the outer shell gave rise to its popular name, as it is of about the apparent size of Jupiter.

The nebula has a visual brightness of 7.7 mag, while it is only 8.6 mag photographically. The central star, cataloged as HD 90255 and is of visual magnitude 12.1. Its distance is not wellknown, but estimated at some 2,500 light years; another estimate is about 1,400 light years.

This planetary nebula is most frequently called the Ghost of Jupiter, or Jupiter's Ghost, but it is also sometimes referred to as the Eye Nebula, or the CBS Eye.

The image above was obtained by Alan Chen on March 28, 2003, with a 12" Meade SCT at f/10, on a Losmandy Titan mount, and with a Starlight Express MX7C CCD camera. It was composed from 34 frames, exposed 1 minute each and self-guided.

The Ghost of Jupiter, NGC 3242, image on the right was obtained by Burness Ansell during his stay at the Advanced Observing Program of the Kitt Peak National Observatory's Visitor Center. He used the AOP's Meade 16-inch LX200 Schmidt-Cassegrain telescope, operating at f/10, and the AOP's SBIG ST8E CCD camera, with color filter wheel. The image is composed of four exposures, taken at exposure times Luminance: 18 min, Red: 2 min, Green: 2 min, and Blue: 4 min.
Credit: Burness Ansell/Adam Block/AURA/NOAO/NSF