Sketch the positions of the equatorial belts and Polar Regions first. Carefully
estimate their widths and extent and where, in terms of latitude, they begin and
end. Next, place the less apparent belts and zones on your sketch as they
appear on the planet. Work on one hemisphere at a time.
Next, place features within the belts and zones using Jupiter's central meridian
(an imaginary line from top to bottom) to help you gauge the distances. Finally,
carefully shade your sketch to duplicate what you see. One technique some
observers say works to bring out additional detail on Jupiter is to focus the eye
on a spot halfway between one of the poles and the equator — but don't actually
look at the spot. Concentrate on seeing and sketching detail in the polar area.
Repeat for the other hemisphere.
Astronomers estimate that 60 percent of all the stars in the Milky Way Galaxy are
double or multiple stars. These stars appear as one to the unaided eye, but many
may be resolved into pairs with the help of a telescope. I don't think there's an
amateur astronomer I know who doesn't enjoy observing double stars. It is fun,
easy, rewarding, doesn't take a complicated setup, you can observe from within a
city, and challenging objects exist for every size of telescope.
In addition to where the double star is in the sky and how bright each component
is, there are two quantities with which a double star observer should be familiar.
The first is the "separation" of the pair. This number is given in arc-seconds, and
it is simply the distance between the two stars.
The second quantity is the "position angle." This is the angle, measured from
north through east, of the fainter of the pair (the "companion," or "secondary")
from the brighter (the "primary"). For instance, if the companion is due north of
the primary, its position angle is 0°. On the other hand, if it is due east, 90°, and if
midway between south and west, 225°.
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