M 31 (2)

Now, in August 2020, as M 31 is visible again, so I observed it again, this time using the Canon EF 70-200 mm f/4L USM, which has, due to its shorter focal length (f = 200 mm), a wider field-of-view compared to my APO refractor (see above). Also, in 2020, I am using the new Celestron StarSenseModule for quick semi-automatic star and polar alignment of the CGEM mount, and the focus was much better this time. 

This time, compared to the 2018 picture, the exposure (5465 sec) was of sufficient duration and I also selected a higher sensitivity (Iso 1600). In total 47 light frames were obtained, together with a number of dark, bias and flat frames. Image processing was done using PixInsight V 1.8.8.-5

M31, Andromeda galaxy, 19 August 2020, Vorst, Canon EF 70-200 mm f/4L USM, 

Canon EOS 600D, UV-IR filter, 1600 ISO, f = 200 mm, 

5465 sec. Image processing with PixInsight

 In August 2022, M31 was the target again, this time with my new ASI 1600mm pro monochromatic camera. Average gain (139) and cooling @ -10C using L, R, G, B filters. The galaxy merely fits into the FOV (about 180’). I obtained 32 L frames and 10 frames for each R, G, B, respectively. Total exposure = 32 x 120 sec + 30 x 120 sec.

M31, Andromeda galaxy, 07 August 2022, Kempen, William Optics APO 110 mm, f/7, LRGB filter, ASI1600mm pro,

gain 139, T = -10C. 32 x 120 s (L), 10 x 120 s (R), 10 x 120 s (G), 10 x 120 s (B). Image processing with PixInsight V1.8.8

In August 2025, M31 was observed again. The galaxy is larger than the field-of-view (1.2 x 0.9 deg) of my telescope, therefore I  made two images: located on either side of the bright nucleus. Both sub-images were then combined into one mosaic image of M 31, shown below. Compare with M31 imaged in 2022.

M31, Andromeda galaxy, 25 August 2025, Kempen, William Optics APO 110 mm, f/7, L- filter (UV-IR cut), ASI1600mm pro,

gain 139, T = -10C. 4800 s (L).  Image processing with PixInsight V1.9