Finally, there are several challenging MCG and anonymous galaxies in the 16th magnitude range that are visible in a 17.5-inch scope. Shakhbazian 49 is a very challenging compact group of compact galaxies situated just 20' NW of the NGC 3158 cluster. This is a marginal object in my 17.5-inch. Perhaps a 20 to 25-inch scope would be able to cleanly resolve individual members. A remarkable chain of galaxies, HCG 56 is located a mere 7' south of the bright barred spiral NGC 3718.
Photographs reveal five members with the central trio appearing as an interconnected chain chain.
Observers using Lord Rosse's 72-inch reflector examined the field of NGC 3718 four times between 1852 and 1868 and missed this galaxy chain, so just detecting this group should be considered an accomplishment. I took another look last July at the Sierra Buttes, in the Gold Lakes Basin region of the California Sierras. Although easily visible with averted vision, this object was fainter than recalled from earlier observations.