Object of the Week February 1, 2015 IC 3568, The Lemon Slice Nebula -or- the Baby Eskimo Nebula
IC 3568, PK 123+34.01, UGC 7731, PN G123.6+34.5, ARO 56

Planetary Nebula - Camelopardalis

R.A.: 12h33m06.8s
Dec.: +82°33'50" (2000)

Size: 18"

Mag: 11.1 V
Mag: 11.4 B

IC 3568 is a tiny but bright planetary nebula only about 8 degrees from Polaris, so it is available most of the year to those of us in the mid latitudes of the northern hemisphere. Apparently Jay McNeil gave it the 'Baby Eskimo' nickname, but a look at the Hubble photo clearly illustrates why most folks now use its more familiar handle, the 'Lemon Slice' nebula. As per Balick et al, 'morphologically it is one of the simplest planetary nebulae in the sky.' http://adsabs.harvard.edu/full/1987AJ.....94..948B

ic3568.jpg

Interestingly, Megastar shows a galaxy, UGC 7731, as being co-located at this position, and Simbad additionally shows this PN to have a LEDA designation, so at some point in the past it must have been assumed to be a galaxy. The NGC/IC Project does not have data on this fellow.

My own best observation of this guy was made during the Oregon Star Party in 2001, where I enjoyed the finest star party skies ever! SkyTools indicates a diameter of 18 arc-seconds, but a viewed under great skies with a 20" f5 Obsession it didn't seem to be that large, it appeared to be perhaps 12 or so arc-seconds across. The central star, listed at mag 13.4, was glimpsed only at fairly high power, about 400X or so, largely because the high surface brightness of this planetary tends to mask it. The disk itself showed only a slight bit of color, essentially gray but maybe with a bluish or greenish tinge. Whatever the tint, it was very subtle. I observed no structure within the nebula whatsoever, the perfectly round disk simply faded away to a fuzzy and vague outer edge. An OIII filter increased the contrast but did not help to reveal any structure.

IC3568.gif

There is a mag 14 star in the field, about 12 arc-seconds mostly west and just a little south (PA 263). Together they almost look like a double star with one member being quite fuzzy.

As always, give it a go and let us know!