exactly does "tracking"
astronomical objects mean
and why is it important?
without a telescope, the sky appears essentially fixed
and unmoving. Viewed through even a small telescope,
however, the situation is quite different. Although the
sky (the "celestial sphere" containing all the stars,
planets, and other objects) is, in fact, essentially
fixed, the Earth turns underneath the sky once every 24
motion is magnified by the telescope, to the point where
astronomical objects appear to move through the
telescope's field of view in 10 to 30 seconds. It is
therefore important for the observer to be able to
follow, or track, objects as they move through the
telescope models provide several different means of
accomplishing this tracking requirement, from the manual
tracking controls of the Model NG-60, for example, to
the computerized tracking of the LX200GPS series.
are Right Ascension and Declination?
Analogous to the Earth's longitude and latitude, the
celestial sphere is divided by a grid of lines that are
used to define the positions of every object in the sky.
Just as the location of, say, New York City, is defined
on Earth by its longitude and latitude, so the position
of the Orion Nebula in the sky is defined by its Right
Ascension and Declination.
Right Ascension is the
celestial analog to the Earth's longitude, and
Declination is the celestial analog to the Earth's