M81 & M82

M81 is a fairly bright galaxy thanks to its relative closeness, and on a night particularly suited to observing it can even be spotted with simple binoculars; an instrument such as a 60-80 mm refractor shows it as a featureless bright patch, extending a few arcminutes and elongated in the NNW-SSE direction. A more powerful telescope, around 140-150 mm, reveals the structure of the nucleus, much brighter than the outer regions, which seem to fade gradually into the darkness of the background sky; with 250-300 mm instruments the first spiral structures also become visible, as brightness variations in the halo around the nucleus. In long-exposure or composite photographs, the field of view of this galaxy and its neighbour M82 can appear pervaded by a web of intricate nebulous filaments: this system of gas and dark dust is part of the Integrated Flux Nebula, a high-galactic-latitude cloud belonging to the Milky Way.