Deneb in the constellation Cygnus, the Swan
Right overhead at 7 pm there’s a relatively bright star. Its name is Deneb, derived from an Arabic word meaning, “the tail.” This is the tail of the swan Cygnus.
Deneb, together with two other bright stars which lie slightly to the west at this time, forms a large triangle. It’s known as the Summer Triangle because of its prominence in the summer sky.
Deneb is a remarkable star. At a distance of roughly 1600 light years from earth, the light that we’re seeing here left the star 1600 years ago, around the time of the fall of Rome.
For us even to see this star, it must be incredibly bright, much brighter than our Sun. No planets could likely survive in orbit around it.
This is a famous star in Chinese mythology as it marks one side of the bridge of magpies that crosses the Milky Way river to allow two lovers, the Cow Heard and the Weaver Maid, to meet on the seventh day of the seventh month. In the Chinese lunar calendar, this is usually celebrated in August. The Cow Heard and the Weaver Maid are the stars Altair and Vega, the two other stars in the Summer Triangle.
Earthshine is running an fundraising campaign to purchase a planetarium. It is called "What is That Star Called?" Please help us reach our goal. Thanks!