| Emission nebula | |
|---|---|
| Planetary nebula | |
 | |
| Observation data:J2000epoch | |
| Right ascension | 10h 24m 46.1s[1] |
| Declination | −18° 38′ 32.6″[1] |
| Distance | 4800±500[2] ly |
| Apparent magnitude (V) | 8.60 |
| Apparent dimensions (V) | 25″ |
| Constellation | Hydra |
| Designations | Ghost of Jupiter, Jupiter's Ghost, Eye Nebula,Caldwell 59 |
| See also:Lists of nebulae | |
NGC 3242 (also known as theGhost of Jupiter, Eye Nebula orCaldwell 59) is aplanetary nebula located in theconstellationHydra.
William Herschel discovered thenebula on February 7, 1785, and catalogued it as H IV.27.John Herschel observed it from theCape 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 inJ. L. E. Dreyer'sNew General Catalogue of 1888.
This planetary nebula is most frequently called theGhost ofJupiter, orJupiter's Ghost due to its similar shape to the planet, but it is also sometimes referred to as theEye Nebula.[3] The nebula measures around two light years long from end to end, and contains a centralwhite dwarf with an apparent magnitude of 11. The inner layers of the nebula were formed some 1,500 years ago.[4] The two ends of the nebula are marked byFLIERs, lobes of fast moving gas often tinted red in false-color pictures.[5] NGC 3242 can easily be observed with amateur telescopes and appears bluish-green to most observers. Larger telescopes can distinguish the outer halo as well.[6]
At the center of NGC 3242 is anO-type star with aspectral type of O(H).[7]
