Asterism - Little Orion

[Hughsie]

This was another trial session with the 8" Ritchey Chretien fitted with the ZWO ASI294MC Pro to review collimation. I'm not particularly bothered by the satellite trails visible in the image as the main agenda item was star shape, However, I do seem to have picked up a circular 'blotch' just near the center which at first sight could be a dust mote but I cannot see anything on the mirrors, filters or camera sensor.

Then again, I say 'filters'. I set up to image with the Optolong Dual Band L-eXtreme filter but didn't actually install it! I really should give this up

Anyway, here is the asterism Little Orion. The star in the upper left is 'Betelgeuse' and is positioned in front of the 'Florida' arm of the North American Nebula. For anyone wishing to visit this target the RA/DEC is 20h 55m 51.1s and +43d 37m 56.2s.

The image represents 38 subs x 300s using no filter whatsoever.

 

Edited August 6 by Hughsie

[Roy Foreman]

Excellent. I know the star you mean as I've imaged this area many times but never noticed the asterism. I will have to take a closer look at one of my images and seek it out. Love your star spikes, and they are real ones too !

[fireballxl5]

Coincidently my first image of the summer was of northern Cygnus, though at slightly less resolution using my Samyang 135mm / ASI071MC Pro combo. Here's the same asterism.

[Hughsie]

Further update.

Last night I tried again this time ensuring the Dual Band L-eXtreme was installed in the filter wheel. As this was the first time of using this filter I wanted to see what the results would be like and I also wanted to know what was producing the 'blotch' on the image.

The blotch turns out to be condensation on the ASI294MC sensor. The scope/camera had been mounted all afternoon and as I was not pressed for time I started the cool down process of the camera late evening and reduced the sensor temp to -10c over 30 minutes. This resulted in a condensation. I then warmed the camera to +2c and then reduced the temp in increments of 2c every 10 minutes and no condensation formed. It was a bit of a faff so on the off chance the desiccant tablets are saturated I have ordered replacements from FLO and will dry off the old ones in the microwave and keep them as spares. In fact an email confirming the order has been completed has just popped up on my monitor. FLO are always watching!

The image below is a combination of the L-eXtreme data for the background and the original stars from the earlier image. More data is always needed but I like the result.