This week the small, admittedly faint constellation of Lacerta, the lizard, is perfectly placed for northern hemisphere viewers to identify. This grouping does not date to antiquity but was defined by the astronomer Johannes Hevelius in 1687, who originally proposed the name Stellio after the Mediterranean lizard species Laudakia stellio.
The constellation is located between the brighter ones of Cygnus, the swan, Cassiopeia and Andromeda. Cassiopeia in particular can help locate it because both constellations share a “W” shape. In the case of Cassiopeia, the shape represents a queen sitting in her throne, whereas for Lacerta, the shape is made by the constellation’s brightest stars. Brightest in this context means only of the fourth magnitude.
To track them down, find the darkest sky you can and wait for your eyes to adjust to the dark. Then the constellation will be easily visible. The chart shows the view looking high in the southern sky from London at 2000 GMT tonight. The view remains essentially the same all week. Being located so far into the northern celestial hemisphere, however, means that Lacerta becomes increasingly difficult to see south of the equator. From Sydney, Australia, it is just visible on the northern horizon around mid-evening.
