Herschel 171, also known as NGC 4258 and Messier 106, is a galaxy with classification SBbc in the constellation of Canes Venatici. It has a diameter of ~124,000 light-years. There are a number of additional galaxies in the image. Just to the west-northwest lies NGC 4248. Further away to the north-west of Herschel 171 lies NGC 4220. To the west lies NGC 4346 and to the west-southwest NGC 4217.The images comprise 6 x Luminance (300 seconds each), 0.101m f/5.4 Tele Vue refractor with FLI ML16200 camera at an altitude of 65 degrees on 28 March 2017. The fields of view of the top and bottom images are 132’ x 132’ (2.2 degrees square) and 42’ x 42’, respectively.