10
TRACKING CELESTIAL OBJECTS
The Earth is always rotating about its polar axis, completing one
full rotation every 24 hours. This is what defines our “day”, and we
see it in the apparent movement of sun and stars throughout each
rotation. In the same way that the sun rises and sets each day,
the stars in the sky rise and set each night. The motion translates
to a rate of approximately .25° per minute, or 15 arc-seconds per
second. This is commonly referred to as the sidereal rate.
As you observe any celestial object, remember that it is in motion.
You will need to continuously update your binocular position
throughout a viewing session, most easily done using your tripod
adjustments. As an object begins to leave your field of view,
adjust your position in the correct direction and bring the view back
to center.
Remember, your binoculars achieve a high level of magnification,
which shrinks your field of view accordingly. Objects will appear
to move faster at high magnification, and frequent positional
adjustments will need to be made.
ASTRONOMICAL OBSERVATION TIPS
