On Nov 16, 2021, at 2:40 PM, Roland Christen via groups.io <chris1011@...> wrote:



Hello Astronuts,

This is image #2 from my Hawaiian observatory. The image consists of 60 x600 sec LRGB subs. Imaging scope was the 175EDF at F7.5 (no flattener or compressor, just straight on).

To me it looks like a glazed donut, but it's also known as the Spare Tire Nebula. :^))

What's interesting is that there are no dust defects visible in the image, even though I did not use any flats. They are there, but just not visible because the sky is so dark in Hawaii that there was essentially no background flux. I did get several satellite trails in the red subs early in the morning. Median combine did a fair job of minimizing them

https://www.astrobin.com/p8jrgv/0/

Rolando