Imaged the galaxy M104, the Sombrero Galaxy on the nights of April 21, May 10, and May 11, 2023.  M104 has an apparent magnitude (v) of 8 and an apparent size of 9 × 4 arcsec.  This target is pushing the limits this imaging setup and would benefit from some additional focal length, but I've been interested in capturing it for some time and was glad to finally add it to my collection of galaxy images.

Per Wikipedia (reference: https://en.wikipedia.org/wiki/Sombrero_Galaxy):  "The Sombrero Galaxy (also known as Messier Object 104, M104 or NGC 4594) is a peculiar galaxy of unclear classification[5] in the constellation borders of Virgo and Corvus, being about 9.55 megaparsecs (31.1 million light-years) [2] from the Milky Way galaxy. It is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. [6] It has a D25 isophotal diameter of approximately 29.09 kiloparsecs (94,900 light-years), [1] making it slightly bigger in size than the Milky Way.It has a bright nucleus, an unusually large central bulge, and a prominent dust lane in its outer disk, which is viewed almost edge-on. The dark dust lane and the bulge give it the appearance of a sombrero hat (thus the name). Astronomers initially thought the halo was small and light, indicative of a spiral galaxy; but the Spitzer Space Telescope found that the dust ring was larger and more massive than previously thought, indicative of a giant elliptical galaxy. [7] However it is now believed that the Sombrero Galaxy is a Lenticular galaxy combining both the characteristics of an elliptical galaxy and a spiral galaxy." 

Imaged with a William Optics GT81 at F4.7 (382 mm focal length) using Flat6A II field flattener/0.8x reducer, UVIRcut filter, and ZWO ASI 533MC Pro.  Total integration time of 3 hours: 9 subs at Gain = 100 with an exposure time of 120 sec.

Pre-processed using Pixinsight's weighted batch pre-processing script (WBPP) to perform calibration, debayering, registration, local normalization, and integration.  Background removed using GradXpert.  Initial post-processing in Pixinsight:  spectrophotometric color calibration, blur x terminator, and noise x terminator.  Unscreened stars using StarXTerminator, then further processed the starless and stars images separately:  generated rangemask and applied for subsequent steps for starless image, generalized hyperbolic stretch, curves transformation, HDR transformation using EasyHDR script, local histogram transformation, and color saturation adjustment, and lastly re-screened stars using PixelMath. 

Original version:  Crop of final M104 OSC RGB image

Rev B:  Crop of final M104 OSC RGB image, starless version

Rev C:  Crop of final M104 OSC RGB image, inverted version

Rev D:  Final M104 OSC RGB image (full image)