The huge halo of NGC3242
NGC 3242, commonly known as the Ghost of Jupiter, is a planetary nebula located in the constellation Hydra.
William Herschel discovered the nebula that later was catalogued by Dreyer as NGC 3242. After a star like our Sun completes fusion in its core, it throws off its outer layers it a striking display called a planetary nebula. NGC 3242 is such a planetary nebula, with the stellar remnant white dwarf star visible at the center. While the planetary nebula's core measure only about 16" x 26" in diameter, NGC 3242 is surrounded by a first fainter shell and by another very faint giant halo measuring almost half degree in diameter, same as the full Moon, with a prominent arc containing both strong emissions of Ha and OIII. This huge halo was first discovered on the Palomar DSS plates and later confirmed to be related to the planetary nebula itself.
Apo TEC140 (140/f7.2) - FLI Proline 16803 - Ha (510m) OIII (540m) R (90m) G (90m) B (110m) - Warrumbungle Observatory, Coonabarabran, NSW, Australia