Alpha Andromedae which has the traditional names Alpheratz (or Alpherat) and Sirrah (or Sirah), is the brightest star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 in the constellation

Constellation

In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 of Andromeda

Andromeda (constellation)

Andromeda is a constellation in the northern sky. It is named after Andromeda, the princess in the Greek legend of Perseus who was chained to a rock to be eaten by the sea monster Cetus...

. Located immediately northeast of the constellation of Pegasus

Pegasus (constellation)

Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:...

, it is the northeastern star of the Great Square of Pegasus. As a connecting star to Pegasus, it is also known as δ Pegasi, though this name is no longer used (another such doubly named connecting star is β Tauri).