A week ago on March 17, the clear skies continued to be available and I decided to have a go at observing the Leo Triplet of galaxies consisting M 65, M 66 and NGC 3628. I have observed this trio before (see below) but I wanted to try this time with the Dwarf 3. It was two days to new moon at this time and the skies were nice and dark. Here is what I obtained after 459x15s (nearly 2 hours) of observation:-
M65 is in the centre of the frame. M66 is to the lower left of it and NCG 3628 (the Hamburger Galaxy) to the upper right. The other prominent galaxy at the far right of the image is NGC 3593. Here the gain was set to 60 and the astro filter was employed in the Dwarf 3. The image was subsequently processed in Stellar Studio using auto settings. Binned x2 and sharpened slightly in Photoshop. The first frame was taken at 20:07 UT and the last at 22:57 UT. Midpoint 21:32 UT. This group of galaxies also appears in Halton Arp's catalogue of peculiar galaxies (Arp 317).
Almost exactly ten years ago I obtained this image using my Celestron NexStar 102 SLT:-
This was 11 minutes of exposure (22x30s) using a D90 at prime focus (ISO 3200) and was taken on the 5th April 2016. There is obviously a problem with pink halos around the stars. For comparison I have rotated, scaled and cropped my Dwarf 3 image above to match this and this is the result:-
To get the same exposure on the Dwarf as 11 minutes on a 102mm aperture telescope I would need (102/35)²x11 = 93 minutes (around an hour and a half). I have gone a bit deeper than this but currently I think I know which telescope I would rather be using!
All text and images © Duncan Hale-Sutton 2026
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