Pleiades (M45) and Mars...

Conjunction of M45 and Mars

Object: M45 (the Pleiades or Seven Sisters), Mars

Type: Open cluster and planetary conjunction 
Constellation: Taurus

Date: March 5th., 2021
Equipment: ATIK 460EX with EFW2, Samyang 135mm lens @f2.8, Vixen GPDX mount, guiding with Lodestar X2/PHD

Subframes: 20 x 10s each for luminance, red, green and blue, flats, no darks (hot pixel removal in Astroart).

This image was an unplanned shot; I was attempting to gather 600 second subs for my Sh2-273 project, but clouds began to intermittently drift over, making long subs impossible. Rather than waste a rare clear, dark and moon/free evening, I swung the rig around to M45 and its conjunction with Mars. The planet is long past opposition but it was still as bright as nearby Aldebaran, and was only about 2 degrees from the cluster.  As it won't be this close to the Pleiades until March 2036,  I thought it was worth capturing.

The short and numerous exposures allowed me to reject the cloud-fogged ones. I was pleasantly surprised by the amount of cluster nebulosity captured given the very short exposure length.

Each of the R, G and B channels were stacked in Astroart, and a nasty gradient removed with the AA plug-in.  An RGB image was prepared in PaintShop Pro. No stretch was applied, but a mild Gaussian blur was used to smooth out the rather blocky stars (the 4.54u pixels are rather under-sampling at 135mm).

The luminance stack was similarly gradient-scrubbed then blurred, and star reduction applied in PSP (background selected with "magic wand", inverted to select stars, selection expanded and feathered by a few pixels, then "eroded").  A mild edge-preserving smooth was applied to reduce noise, and a selective mild stretch applied to bring up the Pleiades luminosity was applied.  This was then pasted over the RGB one in luminance mode to given the final image.