Sky Notes · Constellations

How to find Cassiopeia from Hyderabad

The bright W in the northern sky: when to look, where to face, and the five stars that make it.

By Bhanu Prakash, astronomer · Hyderabad

Cassiopeia is one of the easiest constellations to recognize: five bright stars in the shape of a W, or an M depending on how it is turned. It is also the constellation behind the expertise section of this site.

When to look

From Hyderabad, Cassiopeia is best on autumn and early-winter evenings. In late November it is highest in the north at around 9 PM, roughly halfway up the sky. In other months it is lower, and in spring evenings it sits close to the northern horizon.

Where to face

Face north. Find a spot where trees and buildings do not block the northern sky. Look about halfway up from the horizon for a zigzag of five stars of similar brightness.

The five stars

From one end of the W to the other, the stars are Segin, Ruchbah, Navi (Gamma Cassiopeiae), Schedar and Caph. Schedar has a slightly orange tint. Navi changes in brightness over time, and is sometimes the brightest of the five.

Why it never seems to move far

Cassiopeia lies close to the north celestial pole, so as the Earth turns it swings around Polaris instead of rising high and setting like the stars of the south. Watch it over a few hours and you will see the W slowly rotate.

What to look at next

With binoculars, sweep along the W: it lies in the Milky Way, and the field around it is rich with faint stars and small star clusters.