Alpha Cassiopeiae

α Cassiopeiae
Alpha Cassiopeiae, "Schedar" (Breast), is a giant yellow star with a wide ninth magnitude companion.

As the constellation is circumpolar, it can be studied nearly any time of the year. To find Cassiopeia first locate the Big Dipper (Plough in the UK). Now draw a line from the ‘pointer stars’ (beta and alpha UMa) through the Pole Star. Don't stop there, but continue the line to about the same distance on the other side of the Pole Star. You'll encounter a very wide "W" or "M", depending on the time of year. (For convenience sake, we'll confine ourselves to describing it as a "W".)

Note that North is indicated on these charts. Always bear in mind the orientation of circumpolar stars.

You can also find Cassiopeia through Andromeda; the three stars of Andromeda are somewhat brighter and form a backdrop to Cassiopeia: naked eye.

The principal stars are just wide enough not to be in the same field of view with many binoculars.

There are several attractive binaries in the vicinity of the great 'W'. Placing alpha Cassiopeiae nearly centred in your glasses, you'll find a fine binary, eta Cas to the northeast, considered the finest binary in the constellation by many observers.

This star is a multiple system (9 companions). Three of the companions are accessible, two of which form very wide binocular objects:
      AB: 3.5, 7.4; 323º, 13.2" (yellow/red)
      AG: 3.5, 9.5; 258º, 294"
      AH: 3.5, 8.4; 355º, 684.7"

Now move over to beta Cas for another delightful, but telescopic, binary, and a splendid open cluster.

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