Alpha Lacertae may be the brightest of the stars in the
constellation of Lacerta, but it has little competition among
this faint group - its apparent magnitude is just +3.8. It lies
more than a hundred light years from the Solar System.
Physically, Alpha Lacertae is a main sequence star and, like
most stars (including our own Sun), generates energy through the
fusion of hydrogen into helium. It is, however, about ten times
as massive as the Sun, and consequently much more luminous. It
has a high surface temperature of c.10,000 K, and so shines with
a fierce white light. Alpha Lacertae is a binary system: the
main white star has an orbiting companion, which is much fainter
at magnitude +12.0.  From Earth, Alpha Lacerta lies in the
northern part of its home constellation of Lacerta, against the
backdrop of the Milky Way. It can prove difficult to pick out,
since it is not noticeably brighter than many of its
neighbouring stars; it forms the second point in the descending
'zig-zag' that forms the backbone of th