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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.”
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
Precision Polar Alignment - The Drift Method
Using this method, azimuth and altitude are adjusted separately until the effects of star
drift are eliminated. This method is good for Northern and Southern Hemisphere users.
• Azimuth adjustment
Select a star on the celestial equator and meridian (i.e., Hour Angle = 0° and Dec. = 0°).
• If, over time, the star drifts S in the eyepiece then the southern end of the polar axis is pointing
East of the Celestial Pole.
•If the star drifts N then the southern end of the polar axis is pointing West of the Celestial Pole.
• Altitude adjustment
Select a star in the East (and/or in the West) low on the horizon and in the southern hemisphere of the
Dec. = 0º.
• If the star in the East drifts N the elevation is too low.
• If the star drifts S the elevation is too high.
For more information on Polar Alignment on the Southern Hemisphere, visit Astronomical Society of
South Australia website at
www.assa.org.au/resources/equipment-reviews/polar-alignment/
