Abell 21, a planetary nebula in Gemini, also known as the Medusa Nebula due to the appearance of striations in the nebulosity resembling the snakes of Medusa's hair.
Taken on the night of 12-13 Feb 2019 at Whorley. I used my 5” Explore Scientific refractor with no changes to the configuration. Imaging encompassed 120 light frames of 30 seconds each across luminance, red, green and blue filters, equating to 1 hour of light data.  Full calibration data was taken after the lights as well. Significantly, this is my first full rgb imaging session to include autoguiding throughout the imaging. I did, at the time, feel the guiding was being overly aggressive, and that the RA axis was over-correcting. However, the finished product, with round stars required no deconvolution tells me the guide must have been okay.

The nebula is an old planetary, and considered to be dim (8” scope recommended...) Well, 5” works too apparently.

Processing of the lights and calibrations were all on PixInsight. Will describe that process in an update.

Regards,
Mark J