User Manual

18
EXOS II MOUNT SET UP / POLAR ALIGNMENT PROCESS
Finding the Polar Star (for Northern Hemisphere only)
Star hopping is a technique used by amateur astronomers to navigate the night sky. By using easily
recognizable constellations and asterisms as a guide, an observer can locate stars and other objects.
Polaris, which is commonly referred to as The North Star, can be located quickly using star hopping.
Polaris is far from the brightest star in our night sky, but for centuries it has served as a navigational
beacon representing true north because it lies extremely close to the north celestial pole. Although it
has not always held this lofty position, Polaris’ current reign has lasted for centuries and will continue
for centuries to come.
Follow these steps to locate Polaris using the star hopping method:
1. Locate the Big Dipper asterism in the Ursa Major constellation. The popular pattern is defined by
seven stars. The two stars on the front edge of the Big Dipper’s “bowl” are Merak and Dubhe.
2. Draw an imaginary line from the bottom star (Merak) on this front edge through the top star
(Dubhe) on the front edge. Follow the line to the first bright star you see. That should be Polaris
(Fig. 2a).
3. To verify your finding, locate the Little Dipper asterism. Polaris is the anchor star at the end of the
Little Dipper’s (in Ursa Minor) “handle.”
Using the Optional Polar Alignment Viewfinder (for Northern Hemisphere only)
1. Use a compass to find north. Physically position the mount so that the front leg is aimed toward
Polaris. Once this is done, level the mount.
2. Remove the caps covering both ends of the polar alignment viewfinder (6, Fig. 1a). Loosen the
Dec. lock (1, Fig. 1a) and rotate the telescope declination so that nothing is obstructing your view
through the Polar Alignment Viewfinder. (Note that the telescope will be perpendicular to the
polar axis during this exercise.) Retighten the Dec. lock.
3. Loosen the R.A. lock (4, Fig. 1a). While looking through the Polar Alignment Viewfinder, rotate the
right ascension until Polaris and the four stars that are etched on the reticle are roughly aligned
with the markings (Fig. 3b). Tighten the R.A. lock.
4. While looking through the Polar Alignment Viewfinder, use the azimuth control knobs (5, Fig. 1a)
and latitude adjustment handles (2, Fig. 1a) to fine tune the alignment of Polaris and the four
stars with the markings on the reticle (Fig. 3b). This can be a long process, and you may have
to adjust the right ascension again. In the end, it is unlikely that all five stars will be precisely
aligned with the markings, but it is important to get each one as close as possible.
5. Once you are satisfied with your alignment, loosen the Dec. lock and rotate the telescope to 90°
North so that is once again facing in the same direction as the Polar Alignment Viewfinder.
Replace the caps covering both ends of the Polar Alignment Viewfinder.
BIG DIPPER
POLAR STAR
CASSIOPEIA
Caph
Zeta
Beta
Kochab
Pherkad
Gamma
Eta
Epsilon
Delta
Alpha
Shedar
Cih
Ksora
Segin
Alkaid
Alcor
Mizar
Alioth
Megrez
Phecda
Merak
Dubhe
Fig. 2a