Short Cold Night at Harvard

The December 8 forecast was to be in around 32 by 9PM I decided to keep the night short. Astro-twilight was about 6:05 PM so I  arrived at the town of Harvard parking dark site around 4:30PM. Setup and all star polar alignment went smoothly. I deviated from the original target list dropping  M31 and NGC 1342 while adding M77 and NGC 2024. I probably should have stuck with NGC1342 instead of M77 which would be better imaged at a longer focal length. A combination of the dew hood and an ~8 mph breeze from the north challenged the auto-guider. And, having forgotten to bring my balaclava head covering the wind chill challenged my face during tear down at the end of the night. Fortunately I did remember to bring gloves and hand warmers. The five targets imaged appear below. Additional notes follow the images.

IC 5146

M33 (Triangulum Galaxy)

Messier 77(NGC 1068)

NGC663

NGC2024 (Flame Nebula)

All imaging was done at F/4 (800mm) with Celestron 8 AVX + Starizona Night Owl focal reducer corrector + ZWO ASI294MC Pro. Image area reduced to 3104x2116 pixels. Imaging temperature -10C. Of note, optical configuration was kept assembled and dark frames acquired the following day. Processing was with Autostakkert! I decided to experiment with acquiring dark frames with camera rotated slightly clockwise and counterclockwise from original. These were found to have little effect on post processing. For this reason I will likely acquire flat frames after the night of imaging with a reassembled optical configuration. I'll also return to the Orchard site which has less of an issue with passing cars.

Meade DSI Open Clusters and Nebulae #3

Here are a few more deep sky images acquired with the mothballed Meade DSI IIc. Unfortunately, as said in earlier posts, there's no documentation. Likely they were acquired between F/3 and F5 using an Atik 0.5X focal reducer stacked in line with a Celestron F/6.3 focal reducer. My plan is to image these and images from the previous two posts with the current equipment: ASI294MC Pro, Starizona Night Owl, Celestron 8 AVX.

CR399

NGC 869 and NGC 884

Messier 21

Messier 39

Messier 52

NGC6664

NGC6882

NGC 6883

NGC 6913

Comet Lovejoy and Open Clusters #2 Meade DSI

Comet C/2014 Q2 Lovejoy from April 2015 and accompanying open clusters were taken with the Meade DSI Color II. Quite a bit of noise is evident in these stretched images despite the use of dark frames. Not sure about exposure times. Recent an near future posted Meade DSI astro-images will be targets for future imaging with the ASI294MC Pro. 

Comet C2014 Q2 Lovejoy

Messier 41

M44

NGC1502

NGC1857

NGC2506

Open Clusters by Meade DSI #1

The following are a few never posted open star clusters taken with the Celestron 8/AVX and Meade DSI back on 1/14/2016. Lacking notes I have estimated the fields of view based on ratios of measured object radius and image width. The average FOV was 32x26 arcmin corresponding to F/3.3 indicating inline use of the Celestron F/6.3 and Atik 0.5x focal reducers. Images were made before acquiring an auto-guider and thus are unguided.  The AVX mount's all star polar alignment combined with relatively short exposures yielded nice round star images. 

Messier 103

NGC 1647

NGC 1807

NGC 1817

NGC 2129

NGC 2158

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