Short Chilly Night

I don't usually image planets on the same night as imaging deep sky objects because they involve very different optical configurations. On this particular night, 10/17/2020, after imaging Sharpless-106 (Butterfly Nebula), IC1396(Elephant Trunk Nebula) and NGC7293 (Helix Nebula) the corrector lens on the Celestron 8 was just starting to fog. 

This shortened the night with Mars high up to the east. I decided to reconfigure the scope and image Mars. Typical of Massachusetts seeing was mediocre. With better seeing I think Mars could be sharper. OTOH I am using a one shot color camera which, compared to a monochrome camera with color filters, is suboptimal. It's a compromise I live with for time efficiency.

DSO images were acquired at F/4 coupling the Starizona Night Owl focal reducer, Orion SkyGlow Imaging Filter  and ASI294MC Pro one shot color camera. 

I also could have done better centering IC 1396; which I missed the last night out. I should try to image Sh-106 on a night when imaging smaller targets such as planetary nebulae. Sadly, NGC7293 is in an increasingly light polluted part of the sky to the south of Harvard, MA. Of note, I stack and average images using Autostakkert! I then post process with PaintShop Pro 2021 to which I will devote a future posting. 

UPDATE: After watching Robin Glover's Astrophotography with CMOS Cameras video on effective use of signal/noise,  the three DSOs will be reimaged using 30s or 60s subs for my typical skies.

NGC7293(Helix Nebula) 

6 x 300s, F/4, ASI294MC Pro

IC1396 (Elephant Trunk Nebula)
6 x 300s, F/4, ASI 294MC Pro

Sharpless 106 (Butterfly Nebula)
10 x 120s, F/4, ASI294MC Pro, 

Mars, 2x Barlow (~F/20),
ASI178MC, 1078x768

A night for Open Clusters

Tuesday night promised to be mostly clear and calm with rising humidity. With the likely suboptimal transparency, subpar seeing and night shortening fogging due to humidity the  focus would be on open clusters. The first two targets IC4665 and IC4756 were acquired with 12x15s exposures. The remaining were sets of 12x30s exposure subframes. With the nights calm winds and previous AVX mount gear adustments guiding went very well. By 11 PM the Celestron 8 corrector plate was starting to fog up signaling the end of the session. The 11 images acquired appear below. Update: These images were reprocessed in April 2023 using the free GraXpert gradient elimination app.

IC1665

IC4756

Messier 52

NGC457

NGC869

NGC884

NGC957

NGC6633

NGC6871

NGC6883

NGC7039

NGC7082

NGC7243

Breezy Night at Harvard

On 10/8 I travelled to Harvard, MA on a hunch the gusty winds would die down and clouds clear by the time I started imaging. Astronomical twilight was just after 8 PM. By that time it was still breezy but not gusty prompting me to leave the dew cap off to eliminate its 'sail' effect. While this reduced wind's effect it also allowed some late evening dew to form and stray light pollution from passing cars. 

Targets included IC1396 which I actually missed 😕, IC5146, M13, NGC6888, NGC7293 (Helix Nebula) and Sharpless 155.  NGC7293 was plagued by apparent light pollution in its low southern location.  Of the listed targets only IC5146, M13, NGC6888 and Sharpless 155 are worth showing below. NGC 6888 continues to be a tough target for me even with 300s exposures and directly overhead. At only 120s exposures NGC 5146 and Sharpless 155 were surprisingly accessible. I might try 300s exposures on Sharpless 155 in the future to bring out more nebulosity. 

UPDATE: I now know that it's better to acquire a bunch of 30s to 60s exposures for the equivalent time of 120s to 300s exposures.

M13

NGC 5146

NGC 6888 (Crescent Nebula)

Sharpless 155