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| The chart shows the northeastern
horizon at 8:00 PM on March 29, the night of our star party. Jupiter
at mag -2.4, continues riding high, 70 deg above the northeastern horizon,
near the top right of the chart. Jupiter is about 1 deg from M44,
the Bee Hive Cluster. Saturn, at mag 2.5, is well placed about 60
deg above the western horizon (off this chart), less than a degree from
M1, the Crab Nebula.
The Big Dipper, also known as Ursa Major (the Great Bear) is standing on its handle near the center of the chart. Mizar (mag 2.4) and Alcor (4.0) form a naked-eye pair about 12 minutes apart. Resolving this pair with the naked eye has been used as a test of visual acuity. Alexander the Great is said to have required all of his generals to be able to resolve this pair. Mizar itself is a telescopic binary. Its two components (2.4 and 4.0) are separated by about 14 sec, and are readily resolved in a scope. Mizar was the first binary star to be discovered. More than half the stars in the sky are binaries. Each member of a pair orbits the center of gravity of the system with a period ranging from a few years to many thousands of years. Polaris, for example, has a bright component of mag 2 and a pale blue component of mag 9, orbiting their center with a very long period. A modest scope will readily show the pale companion, about 18 sec from the bright com-ponent. What would our lives be like in a binary system, if we had two suns instead of one? |
You can print a copy of this star chart so you can take it outside.
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