Lacerta is one of the 88 modern constellations defined by the International Astronomical Union. Its name is Latin for lizard, a small, faint constellation, it was created in 1687 by the astronomer Johannes Hevelius. Its brightest stars form a W shape similar to that of Cassiopeia and it is located between Cygnus, Cassiopeia and Andromeda on the northern celestial sphere. The northern part lies on the Milky Way and it also contains the prototypic blazar BL Lacertae. Alpha Lacertae is a blue-white hued main-sequence star of magnitude 3.8,102 light-years from Earth and it has a spectral type of A1 V and is an optical double star. Beta Lacertae is far dimmer, a giant of magnitude 4.4,170 light-years from Earth. Roe 47 is a star consisting of five components. ADS16402 is a star system in Lacerta, around which a planet orbits with some unusual properties. The Jupiter-sized planet exhibits a low density, about the same as cork. This planet is dubbed HAT P-1, EV Lacertae is a rapidly spinning magnitude 10 red dwarf with a strong magnetic field. It is a star that can emit powerful flares potentially visible to the naked eye. NGC7243 is an open cluster 2500 light-years from Earth, visible in amateur telescopes. It has a few dozen scattered stars, the brightest of which are of the 8th magnitude, BL Lacertae is the prototype of the BL Lacertae objects, which appear to be dim variable stars but are actually the variable nuclei of elliptical galaxies, they are similar to quasars. It lent its name to a type of celestial objects. The object varies irregularly between magnitudes 14 and 17 over a few days, centred on a region of the sky without apparently bright stars, Lacerta was apparently not regarded as a constellation by ancient Western astronomers. Johannes Hevelius created the constellation in 1687 and initially christened it Stellio, both Sceptrum and Frederici Honores are now obsolete, while Lacerta still survives. Similarly, the Chumash people of California call this part of the sky Lizard, USS Lacerta was an attack cargo ship in the United States navy named after the constellation. Ridpath, Ian, Tirion, Wil, Stars and Planets Guide, Princeton University Press, ISBN 0-691-08913-2 Ian Ridpath, Stars and Planets Guide, Collins, London
The constellation Lacerta as it can be seen by the naked eye.
Image: Sidney Hall Urania's Mirror Lacerta, Cygnus, Lyra, Vulpecula and Anser