This is one of those retrospective posts of an image I took way back in 2019. IC4604 Session Data Date:  15/04/20219  Time:  17:09 – 17:52 UT Seeing: Unknown Transparency: Mostly Clear,  Temp: Unknown Air Pressure: Unknown Humidity: Unknown  Dew Point: Unknown Wind Speed: Unknown Scope: Televue P127 APO f/5.3  Camera: FLI Proline PL1608  Filter: Astrodon Ha Calibration: Dark and Flat subtracted. A remote imaging session using T9 in Siding Springs Australia. I know this…