ABSTRACT
Lacerta was added to the sky in 1690 by Hevelius; its brightest star is Alpha, and there is little of immediate interest to the user of a small telescope. In Cygnus, note the North America Nebula, near Deneb, and also the Mira variable U, closely left of the little pair made up of Omicron and Omicron; U Cygni is rather brighter than it was at the time of the other image, and its colour is more evident. The Andromeda Galaxy, M31, is just on the map, to the extreme left-hand edge. In 1936 a bright nova, CP Lacertae, flared up and reached the second magnitude, though it soon faded back to obscurity. The white dwarf pulls material away from its companion, and this material produces an accretion disk round the white dwarf; eventually there is a nuclear outburst in the atmosphere of the dwarf, and gas is ejected at high velocity.
