The immensely rich galaxy cluster Abell 1656 in Coma Berenices with two giant elliptical galaxies NGC 4889 and NGC 4874 at its heart. Both are about 11th magnitude. The face-on spiral galaxy NGC 4921 is at lower left at 12th magnitude; the tilted spiral NGC 4839 is at lower right, also 12th magnitude. The field is peppered with dozens of fainter galaxies from the NGC and PGC catalogues, all around 13th to 15th magnitude. The two bright blue stars are 7th magnitude. I shot this on a less than ideal night, with haze moving in, so this is a stack of only 6 x 8-minute exposures at ISO 1600 with the Canon EOS Ra through the Astro-Physics 130mm EDT refractor at f/6 with the 6x7 field flattener. Shot May 5, 2021. Haze prevented more images to smooth the noise more. Autoguided with the MGEN3 stand-alone autoguider.
The Coma Berenices star cluster, aka Mel 111, with a smattering of galaxies, taken under dark skies on a spring evening. The edge-on galaxy NGC 4565 is at left. I shot this as a test of the William Optics RedCat 51mm f/5 astrographic refractor (which provides a focal lengthof 250mm). This was on the iOptron SkyGuider Pro tracker, a popular portable mount to use with the RedCat. I used it unguided for a set of 2-minute exposures. Of the 20 exposures, 12 were relatively untrailed and so were selected for stacking for this image. This is a stack of 12 x 2-minutes at ISO 1250 with the Canon EOS Ra. Stacked and blended in Photoshop CC. The little RedCat astrograph is very sharp to the corners. The field is about 8° by 5.5°.
The Coma Berenices star cluster, aka Mel 111, with a smattering of galaxies, taken in the deepening twilight and growing moonlight of a spring evening. The edge-on galaxy NGC 4565 is at left. I shot this as a test of the William Optics RedCat 51mm f/5 astrographic refractor. This was on the iOptron SkyGuider Pro tracker, a popular portable mount to use with the RedCat. I used it unguided for a set of 2 minute exposures. But only 6 of the 12 images taken in quick succession were untrailed enough to be usable in the stack, about typical for shooting with a tracker unguided with focal lengths over 135mm. This is a stack of 6 x 2-minutes at ISO 800 with the Canon EOS Ra. Stacked and blended in Photoshop CC. Taken as the waning gibbous Moon was rising this night on May 8, 2020. The little RedCat astrograph is very sharp to the corners. The field is about 8° by 5.5°.
