Viewing Report 21st April 2023

21:48 – 05:47

Out imaging M101 in Luminance again to gather more data before I move onto RGB. I already have some Ha which to be honest is probably not all that useful due to poor signal.

5 mins exposure of M101 uncalibrated

So admittedly the biggest challenge tonight was not having sorted automating a meridian flip, falling asleep and waking up after 1 hour to find I had 50 mins of star trails as the mount had come to a perfectly safe rest and stopped tracking. A quick manual flip and I was back in action

Not tracking at the meridian

Another problem I had, especially on the West side of the meridian was a jump every now and then in the autoguider causing the resulting image to have a jump in it. I eventually suspected the star brightness of the guid star being the issue so I increased the exposure from 7s to 12s. This resulted in an increase in the Relative Star Brightness as shown on the Autoguider Graph increasing from 40 to over 100. It also seems to have resolved the issue.

Relative Star Brightness increased with increased exposure 7s to 12s

The last problem I had tonight was the camera was set to GAIN 139 OFFSET 10 rather than OFFSET 21. This seems to reset in TSX every time I reconnect the camera. So from now on I will make it part of my startup process to set the OFFSET correctly. The impact is slightly dimmer pixels as it is not adding the additional 11 to each one and thus the times for Flats I have need to be increased.

In total tonight I managed to grab around 4 hours 15 mins of good data once I removed problematic frames so 51 x 300s subs. I also took calibration frames, darks, flats and flat darks.