The Sky Today on Saturday, February 21: A ghostly planetary nebula

The Ghost of Jupiter (NGC 3242) has the perfect name for an object on the Ghost Hunt. This planetary nebula sits in west-central Hydra about 35° south of Leo the Lion. At low magnification through a 6-inch telescope, you'll see NGC 3242's pale blue-green disk. Through larger scopes, and at powers above 200x, the interior appears like an eye or a football. Credit: Adam Block/NOAO/AURA/NSF

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February 20: The Coma Star Cluster shines

Head out after moonset this evening to chase down planetary nebula NGC 3242 in Hydra. Popularly called the Ghost of Jupiter, this ball of softly glowing gas appears roughly as large on the sky as the disk of Jupiter through a telescope, which is how it earned the nickname. 

Glowing at magnitude 7.7, NGC 3242 is about 30° high in the south around 11 P.M. local time. The nearest bright star is 4th-magnitude Mu Hydrae, which shines just less than 2° north of the nebula. Once you’re centered on the nebula’s position, you should see a ghostly orb glowing a pale blue — perhaps more reminiscent of Uranus or Neptune, but much larger than either of these planets in the eyepiece. Spanning about 16″ visually through most scopes, see if you can notice how the innermost 10” or so of the nebula are hollower (darker) than the outer regions. An Oxygen-III filter can help enhance the view. 

Sunrise: 6:45 A.M.
Sunset: 5:43 P.M.
Moonrise: 8:35 A.M.
Moonset: 10:46 P.M.
Moon Phase: Waxing crescent (24%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.