Celestron C4.5 User Manual

Motion of the Stars
26 * Astronomy Basics
The daily motion of the Sun across the sky is familiar to even the most casual
observer. This daily trek is not the Sun moving as early astronomers
thought, but the result of the Earth’s rotation. The Earth's rotation also
causes the stars to do the same, scribing out a large circle as the Earth com-
pletes one rotation. The size of the circular path a star follows depends on
where it is in the sky. Stars near the celestial equator form the largest circles
rising in the east and setting in the west. Moving toward the north celestial
pole, the point around which the stars in the northern hemisphere appear to
rotate, these circles become smaller. Stars in the mid-celestial latitudes rise in
the northeast and set in the northwest. Stars at high celestial latitudes are
always above the horizon, and are said to be circumpolar because they never
rise and never set. You will never see the stars complete one circle because
the sunlight during the day washes out the starlight. However, part of this
circular motion of stars in this region of the sky can be seen by setting up a
camera on a tripod and opening the shutter for a couple hours. The pro-
cessed film will reveal semicircles that revolve around the pole. (This
description of stellar motions also applies to the southern hemisphere except
all stars south of the celestial equator move around the south celestial
pole.)The following sections deal with observational astronomy in general.
This includes information on the night sky, polar alignment, and using your
telescope for astronomical observations.
Stars seen near the north M
celestial pole
Stars seen near the celestial
equator
Stars seen looking in the
opposite direction of the
north celestial pole
Figure 5-2
All stars appear to rotate around the celestial poles. However, the
appearance of this motion varies depending on where you are looking in
the sky. Near the north celestial pole the stars scribe out recognizable
circles centered on the pole (1). Stars near the celestial equator also
follow circular paths around the pole. But, the complete path is inter-
rupted by the horizon. These appear to rise in the east and set in the
west (2). Looking toward the opposite pole, stars curve or arc in the
opposite direction scribing a circle around the opposite pole (3).

Celestron C4.5 Specifications

General

Brand	Celestron
Model	C4.5
Category	Telescope
Language	English