Track down the original Cepheid variable
The first known Cepheid variable star lies in the southeastern corner of Cepheus the King. Here's how to find it.
The Andromeda Galaxy (M31) lies nearly 3 million light-years from Earth, while the Virgo cluster of galaxies extends 50 million light-years into the "local" universe. Have you ever wondered how astronomers measure such vast distances? The answer lies in the autumn sky with the extraordinary star Delta (δ) Cephei, which at first glance appears unassuming.