Johann Bayer

Vega, in the constellation Lyra, stands high overhead at nightfall. Arcturus, in Boötes, is well up in the west. And Antares, the heart of the scorpion, is in the south-southwest.

Those stars are also known as Alpha Lyrae, Alpha Boötis, and Alpha Scorpii, indicating that each is the brightest member of its constellation. The names were devised by Johann Bayer, who was born 450 years ago.

Bayer was born in Germany in 1572, although the exact date is unknown. He was a lawyer, and became legal advisor to the Augsburg city council.

Bayer also was interested in astronomy. And in 1603, he published a star atlas. It was the first atlas to cover the entire night sky, including some southern constellations that had been plotted a few years earlier.

Bayer named the stars using a letter of the Greek alphabet followed by the constellation name. So a constellation’s brightest star was alpha, the second brightest was beta, and so on.

There were some exceptions, though — some stars were named based on their position. So while the star Dubhe is Alpha Ursae Majoris, it’s only the second-brightest star of Ursa Major. It marks the lip of the bowl of the Big Dipper, with the other Greek-letter stars tracing the dipper’s outline.

Bayer and a colleague created another atlas, published after Bayer died, that used names from Christianity. But it never caught on — leaving more than a thousand stars named with the Greek alphabet.
 

Script by Damond Benningfield