Friday, April 1, 2022

Recent Activity

I recently acquired a Celestron Motorfocus. What a great accessory. Aside from allowing more precise focusing there is no need to touch the scope (causing shake) or reposition one's self to access a focus knob. One can also enter previously determined number to get close to the focus for a particular optical configuration.  Cool. 

For the first time I visited one of my choice darkish sites it Maryland i.e. McCoy's Landing. It's not as dark as I had hoped thanks to increasing excessive LED street and security in nearby cities but it's better than trying to image from champion light polluter Frederick Maryland. The main target for the night was NGC2359 (Thor's Helmet ). The result below is a start that I hope to improve on when Canis Major returns in late 2022. Also, imaged that night were M48, M67, M81 and Sharpless 274.

NGC2359 (Thor's Helmet)

Messier 48

Messier 67

Messier 81 (Bode's Galaxy)

Sharpless 274

Tuesday, January 4, 2022

First Images of 2022

Based on Clear Sky Charts forecast the night (1/3/2022) promised to be clear, cold and with poor seeing but I decided to go after a few targets including three comets. Of the six scheduled targets only four produced acceptable images. It appears too much Frederick, MD light pollution as well as nearby illumination was leaking into the scope despite the SCT dew shield. All images were 64x30s subframes except for M33 which was 124x30s. Equipment used: Celestron 8 on AVX mount, Starizona Night Owl 0.4X focal reducer/corrector and ASI294MC Pro. Images were stack averaged in Autostakkert! and then stretched and processed with Paintshop Pro. 

Messier 76 (The Little Dumbell Nebula)

Comet 67P/Churyumov-Gerasimenko

Messier 33 - Triangulum Galaxy

Comet 2019L3 Atlas


Tuesday, December 21, 2021

Some Early December Images

These images were acquired in the increasingly sprawling and light polluted city of Frederick, MD. The Whittier neighborhood borders a red and white zone which called for 15 to 20s subframes. Each target was imaged for 180 subframes for cumulative exposure times between 45 and 60min. Equipment: Celestron 8/AVX Mount, Starizona Night Owl with Light Pollution Filter, ZWO ASI294MC Pro. 

M31 Andromeda Galaxy
M42 Orion Nebula
NGC2024 (Flame Nebula), NGC2024, B33(Horsehead Nebula)
NGC7789(Caroline's Rose open cluster)
NGC281(Pacman Nebula)

Sunday, November 7, 2021

I recently watched Robin Glover's excellent talk on deep sky imaging with one shot color cameras. I also read his SharpCap forum write up on setting the exposure time for a site's sky brightness. Robin also gets into the mathematical justification in the write-up which I like. It seems that for my typical F/4 configuration with the Starizona Night Owl focal reducer, exceeding 30sec sub frame exposures offers no signal to noise benefit. This is a real eye opener. Instead, best practice is to collect as many sub frames to achieve a certain total exposure time. For example 120x30sec exposures for an hour. These concepts were played with the six images below from the most recent two imaging sessions. 

NGC 281 (Pacman Nebula)



NGC 6992 (Eastern Veil Nebula)

NGC 7635 (Bubble Nebula)

Messier 13
NGC 7023 (Iris Nebula)

NGC 7380 (Wizard Nebula)


Wednesday, October 20, 2021

A Couple of Globular Clusters (5/15/2021)

Messier 3 and Messier 52 captured in May. Celestron 8 on Celestron AVX mount, Starizona Night Owl, ASI294MC Pro. Exposure 30 x 30s. Guided by Orion Magnificent Mini Autoguider. 

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Messier 3

Messier 52

Wednesday, September 22, 2021

Wow, I haven't posted here since April 12. So, I'll be catching up with some of the my better DSO images acquired over the last five months. A really fun thing about this hobby is when despite owning your hardware for five years you learn a couple of things that make a significant difference. First I recently realized that after doing an All Star Polar Alignment I should realign on the Polar alignment star for better go to pointing accuracy. Also helpful is to display the polar alignment before adjusting it.  The signs of the displayed angles tell you which way to move the tilt and azimuth if the star has not in your finder's field.

The following were acquired 5/14/2021 and averaged from 10 x 2 min exposures using Celestron 8/Starizona Night Owl 0.4x focal reducer and ASI294MC Pro. 

Messier 51 (The Whirlpool Galaxy)
 
Messier 63 (The Sunflower Galaxy)

NGC 4631 (The Whale Galaxy)


Monday, April 12, 2021

Galaxies Despite the Forecast

The NOAA partly cloudy forecast for Harvard, MA on Thursday 4/8 was not optimistic but Clear Sky Charts showed clear skies with average transparency for the night. My local skies were clear so I decided to gamble on the 45 mile trip to Harvard for a night of Coma Cluster galaxy imaging. For the most part the gamble paid off. All images below were averaged from 16 one minute subframes. While experimenting with image processing I found that applying noise reduction immediately after expanding the histogram to brighten the image makes the histogram more manageable. I'll consider elaborating in a future post.

Messier 49 - Giant Elliptical Galaxy

Messier 60(top) & Messier 59(bottom)

Messier 61 - Barred Spiral Galaxy

Clockwise from top Messier 86, NGC4402, Messier 84, NGC4387, NGC4388


Messier 88

Messier 89 (center)

Messier 90

Messier 98

Messier 99

Messier 100

NGC3521