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Gamma Cassiopeia Nebulae
Diffuse Nebula
aka IC 59/63, LBN 620/532
RA: 00h57m30.0s Dec: +6109'00" (Cassiopeia)
Integrated Visual Magnitude: 99.9
Angular Diameter: 10.0' / 10.0'

Minimum requirements to detect: 6-inch? under dark skies


The bright star Gamma Cas is attended by two large wisps of nebulosity, IC 59 and IC 63.  Gamma Cas is the middle star of Cassiopeia, a 2nd magnitude star that is the prototype for a class of eruptive variable stars.  It varies from a maximum of 1.6 magnitude during an eruption to 3.0 magnitude when the mass it is expelling from its equator blocks some of its light.
IC 59 lies about 20' to the north of Gamma Cas.  It is primary a refection nebula, appearing blue in photographs from scattered starlight that is passing through it.  Like the blue sky over your head, some of the light passing through is scattered away, and blue light is scattered more than red.   This light probably originates from nearby Gamma Cas, which may also have shed this nebulous material into the space around it.

IC 63 lies about 20' to the east-northeast.  This nebula is a combination of HII region and reflection nebula.  Unlike a reflection nebula which appears blue, the glowing hydrogen gas appears red in photographs.

It's not clear how much aperture is necessary to observe these nebulae.  For best results you should use an eyepiece that provides a fairly wide field of view (at least 10') yet not so large that you can't keep the bright Gamma Cas out of view.  Because much of the light is due to reflection, neither of these nebulae respond well to OIII or H-Beta filters. 

IC 63 is the brighter of the two and the easiest to spot.  Look for a hazy, fan-shaped region of sky.  It will appear very diffuse with no discernible edges, rather unlike the photograph above.  If you can spot IC 63, then have a try at IC 59.  This nebula is a little fainter and perhaps even more diffuse.  It looks like a roundish patch of sky that is just ever so much brighter than the surroundings.

I had little difficulty observing both of these on a nice dark night with my 18-inch f/4.5 Dob.

Half way between IC 59 and IC 63 lies a small nebula.  This appears to be IRAS 00556+6048.  If you are looking for a challenge, this might prove an interesting target.  I haven't tried for it yet and I'd be interested in hearing if anyone has seen it.  Relatively high magnification, perhaps 300x, might help make it visible.


IRAS 00556+6048.  North is down and east is to the right.
Millennium Star Atlas Vol I Chart 49
Sky Atlas 2000 Chart 1
Uranometria 2000 Vol I Chart 16
Herald-Bobroff Astroatlas B-01 C-04