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| Sandwiched between some of the most prominent and recognisable constellations in the
northern sky lies this innocuous zig-zag of faint stars.
Derivation
The sparse region between Andromeda and Cygnus
was given various names during the seventeenth and eighteenth centuries. This constellation
might have become Sceptrum, the Sceptre, or even Frederick's Glory in honour of Frederick of Prussia. Ultimately, though, the name given
to it by Hevelius in 1687 was to survive: Lacerta, the Lizard.
Stars
There are no significant bright stars in Lacerta. Its
brightest, Alpha Lacertae, is only of
magnitude +3.8, and the constellation contains
no other star above fourth magnitude. Some of these
stars, such as Alpha and
Beta Lacertae, are within two hundred light years of the
Solar System, but are relatively lacking in luminosity. Others, such as
the supergiant 4 Lacertae, are highly luminous
stars, but they are thousands of light years from
Earth, and so appear even fainter than the nearer stars of the
constellation.
Deep Sky Objects
Though Lacerta is relatively lacking in interesting objects, it does lie on the Milky Way, and
as we would expect it is not entirely devoid of features. In particular, there are two open star clusters
in its northern parts, designated NGC 7209 and NGC 7243, which are slightly too faint to be seen without a telescope. These
clusters both lie about three thousand light
years from Earth.
Far, far beyond these clusters is a unusual object lying in the outer regions of the
universe, the first of its kind to be discovered. This is BL Lacertae, a huge
elliptical galaxy with a volatile core. The core's variability can change vary rapidly
over short periods of time, and for this reason BL Lacertae was at first mistaken for a variable
star.
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Lacerta outlines a region that falls between two spiral arms of our Galaxy: hence its stars
are generally distant and faint as seen from Earth.
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