M51 Whirlpool Galaxy
Located about 23 million light-years from Earth, M51 is a spiral face-on galaxy 60,000 light-years across. The brownish color in the arms of the spiral are from HII gas. M51 is believed to be robbing matter from its smaller companion galaxy, NGC 5195, seen above it. Two other tiny galaxies can be seen near NGC5195 - IC 4278 to the left and IC 4277 to the left and above it. North is at the bottom.

Scope/Mount: TS-Optics PhotoLine 130mm F7 APO Refractor with Astro-Tech AT2FF Field-flattener, Celestron CI-700 Mount
Camera: ZWO ASI1600MMC monochrome with ZWO LRGB and Ha, Oiii, Sii filters
Guiding: QHY5L-IIM through Orion Thin OAG, PHD guiding software
Exposure: L:(90) 120 secs @ gain=139, RGB: each channel (10) 120 sec @ gain=139
Software: Nebulosity, Pixinsight
Comment: 04-15-2023, Tierra del Sol, CA, good conditions.