Lacerta, the Lizard, is a small northern constellation of faint stars in the Milky Way between Cygnus and Andromeda, its figure a zigzag like a little Cassiopeia.
At a glance
| stars in the figure | 9 |
|---|---|
| nearest star of the figure | Alpha Lacertae, 103 light-years (31.5 pc) |
| farthest star of the figure | 4 Lacertae, 2,250 light-years (690 pc) |
| depth | the farthest is 22 × farther than the nearest |
Read off the piece’s own catalogue, the same values it draws with.
About Lacerta
Lacerta was introduced by the Polish astronomer Johannes Hevelius, who fitted a lizard into the gap of faint stars between the swan, Cassiopeia and Andromeda. Its brightest stars form a zigzag line that is sometimes called the little Cassiopeia. It lies along the northern Milky Way and is best seen on autumn evenings, high overhead from Europe.
Lacerta gave its name to one of the most extreme kinds of object in the universe. BL Lacertae was long catalogued as a variable star; it turned out to be the brilliant core of a distant galaxy, a jet of matter from around a giant black hole pointed almost straight at us. Such objects are now called BL Lacertae objects, or blazars. Alpha Lacertae, the brightest star of the figure, is a white star.
What you see in the piece
The zigzag looks flat, but Alpha Lacertae is relatively close while the farthest star of the figure lies far out along the Milky Way, so flown out to, the lizard is stretched into a long, scattered trail.
Questions
What is BL Lacertae?
It looked like a variable star in Lacerta, but it is the bright, flickering core of a distant galaxy whose jet points almost straight at Earth, the prototype of the blazars.
How deep is the figure of Lacerta?
The nearest star of the figure is Alpha Lacertae, 103 light-years (31.5 pc) away; the farthest is 4 Lacertae, 2,250 light-years (690 pc), 22 × farther.