Alpheratz (alpha And)

α Andromedae

Alpha Andromedae is better known as Alpheratz (or Sirrah) and forms the head of Andromeda. Many of the other bright stars represent her flowing hair.

It is easiest to find Alpheratz with the naked eye. Beginning at the North Pole draw a line from the Pole Star to Caph (beta Cassiopeia). Now extend this straight line the same distance and you will come to Alpheratz.

Depending on the time of year, this will be your view: Winter; Summer; Late Summer and early Autumn, looking north. And looking south, in late September: culmination

You will have noticed how Alpheratz is one of four stars which make a circular line around Cassiopeia, four equally-bright stars roughly at the same distance from each other. (This quartet is particularly evident just as the brighter stars are beginning to make their appearance, early in the evening.)
     Clockwise, starting from Alpheratz (alpha Andromedae), we have beta Andromedae (Mirach), gamma Andromedae (Almach), and alpha Persei (Mirfak). Remember this quartet: Alpheratz, Mirach, Almach, and Mirfak. (Easy to do: just think of ‘al, mir, al, mir’ and fill in the rest.)

(Note that you'll have to turn the diagram to point toward the North Pole. For example, in the summer Andromeda is turned such that North is toward the west as the observer faces north, so the other stars in the diagram--that form the ‘wedge’ in Pegasus--are to the east of the observer.)
    The first three are the brightest stars in Andromeda, the last one is the brightest star in Perseus (Mirfak also goes by the name of Algenib).

Looking at Alpheratz through binoculars it's obvious that it is very close to Pegasus. In fact this star was once part of Pegasus and is still sometimes known as delta (δ ) Pegasi, as it forms the northeast corner of the Great Square of Pegasus.

There is a fine double star just to the northeast. Place alpha Andromedae on the western edge of your binoculars, then move northeast one binocular field. You should see a distinctive asterism containing both delta and pi And.

Delta Andromedae is a binary with an extremely faint companion, while pi is more accessible:
     delta And: 3.2, 12.4, 299º, 29".
     pi And: 4.4, 7.1; 174º, 35.7".

From delta Andromedae move two binocular fields northeast to beta Andromedae (Mirach). The star is easily found with the naked eye, as delta is midway between the two stars Alpheratz and Mirach. Its red colour makes it fairly easy to identify. Click on that star on the graphic map to find out how to find M31.

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