M40 - Photographing One of Charles Messier's Mistakes

Messier 40, also known as Winnecke 4 is just... two regular stars... that were cataloged by Charles Messier as a Deep Sky Object as he was trying to find a nebula. M40 is in fact not a deep sky object and was added in Messier's catalog as a mistake! It became known as "Winnecke 4" after German astronomer Friedrich August Theodor Winnecke added it in fourth place in its Winnecke Catalogue of Double Stars, in 1863.

M40 is in fact what we call an optical double star, two stars that are not related in any way but look like they are gravitationally attracted due to their close distance and similar size and brightness.

Object Designation: M40

Also Known as: Winnecke 4