2009-09-19
	Remnant CCD electron counts / images of M110
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M110 (Andromeda)  Elliptical Galaxy  Irregular dark dust clouds noted near nucleus

CCD Image (Linear Scale, Cropped) 5 x 60 sec (average combine),  3x3 binning, C Filter 2009-09-20 00:14 h UT  (#389343-47) 12" LX200R  (at f/5.7) + ST-10XME

? Unnamed Companion to M110 (Andromeda)  Faint diffuse object near M110 Is it real ? Seems too far from M31 to be nebulosity/cluster in M31 itself  Could it be a faint companion to M31 ? (Note : M31 lies in direction of bottom left of image) Or is an artifact associated with a flat field problem or some other artifact ?

Annotated CCD Image  (Log Scale, Full Frame) Image details as above

The answer to the mystery object come from consideration of the immediately prior set of images of 3 x 90s CCD images.  These show a saturated patch of pixels at the precise location of the  mystery object. Explanation is that overstaurated CCD silicon retains electrons which  is then slowly released during reading of next few frames.

90s exposure, 00:09h UT (#389340)

M110 - comparison of 1st and 5th frames high contrast views : 1000 ADU range

Top: 60s exposure, 00:12h UT (#389343) Bottom: 60s exposure, 0017h UT (#389347)