Expert: Tom Whiting - 3/23/2005

Question
I have a few questions pretaining to the constellation Lacerta. First of which is, what is Lacertas galactic neighborhood? What are the types and spectrums of the major stars in Lacerta? Finally, is there any mythology related to Lacerta. I know Lacerta means lizard, but when I looked it up in mythology books I cannot find anything related to a lizard. If you can answer these questions or even give me a site at which I can seek my own answers that would help me a great deal. Thanks so much!

Answer
Hi Britney,

You won't find any mythology on Lacerta because it is a
very "recently" named area of the sky (constellations are simply areas of the sky- like states of the USA - for identification purposes only), invented by Johannes Hevelius in the late 17th century....thus no mythology is available, because mythology implies thousands of years ago.
And Lacerta, and other Hevelius filled in blank regions of the sky, are just "too new" and don't go back to Antiquity.

Hevelius invented this constellation, along with others,
(Leo Minor, Lynx, Scutum, Sextans, and Vulpecula) just to
give a name to very blank, star poor, regions of the night
sky. Lacerta is a very small area of the sky of very faint
stars covering only 201 square degrees, and acts as a
"fill in" area of sky for the star poor region between Andromeda and Cygnus on the East-West side, and between Pegasus and Cepheus on the South-North side.

I'm not sure what you mean by...Galactic Neighborhood...
All stars of all constellations are "our neighbors" in the
Milky Way Galaxy, extending outward say 3000 light-years,
which is a 'drop in the bucket' as far as looking across
our Milky Way which has a diameter of over 100,000 lightyears.  So naturally, the very faint stars composing
Lacerta are no different than any other stars comprising
any other constellation....and realize, constellation stars
are not necessarily related....its all 'line of sight'....
in fact, most constellation stars are NOT physically
related, with few exceptions. Even the Big Dipper, the two
end stars are not physically related to the other 5, but
the 5 middle ones are a grouping, the Ursa Major Group,
and they are physically related.

As far as spectral classification, there are no major stars
in Lacerta....remember, it's a star poor region of the sky;
but the primary stars vary in spectral classification just like any other constellation stars. There is no correlation
in spectral classification of the stars of Lacerta...they run the entire gambit of from A type to M type...I see B's and F's and G's and K's in addition to A and M.  The constellation does not have any  hot, bright "O" types which is to be expected, being a very star poor region of the sky.

The most famous object in the constellation is the variable
star BL Lacertae, the prototype of a class of QSO's,
characterized by a lack of emission lines and rapid,
relatively large light variations, varying between 14th
and 17th magnitudes.  The energy output of BL Lacertae
objects are thought to be powered by a huge black hole
encircled by a vortexing accretion disk that is literally
consuming the host galaxy.  Because BL Lacertae is extremely
remote, it is not visually impressive even in large
amateur instruments.

Thus, us amateur astronomers, even me with a 30 inch
portable scope, tend to avoid these blank areas of the
sky, because typically there is nothing bright and interesting to look at in Lynx, Lacerta, Leo Minor, etc.
So we tend to skip over them.

Hope all this helps,
Clear Skies,
Tom Whiting
Erie, PA