Quarter 1 Astronomer Biography: Joann Bayer

       Born in 1572 in Rhain, Bavaria, Germany, Johann Bayer produced the most understandable pre-teloscopic catalog of the stars and established a nomenclature for stars in a constellation that can be seen with the naked eye.  His catalog is considered the first atlas of the sky that represented the stars around the South Pole and mapped the whole celestial sphere.

       Johann Bayer was not originally an astronomer; he studied law.  He moved to Augsburg, Germany to practice law after attending the University at Ingolstadt in 1592.  In Augsburg, Bayer worked more on his astronomy interests, and ended up published his catalog, Uranometria, in 1603.  Uranometria was a mapping of the sky and a classification system for stars in constellations.  Johann Bayer dedicated his book to two leading citizens, and the city counsel of Augsburg, and was appointed the legal advisor to the city.

       Bayer was just an amateur astronomer, but the significance of his work was the innovation of his naming system.  Bayer wanted to clear up the confusion over the previous naming system by precisely identifying and naming each star in a constellation.  Each star was named with a letter from the 24-letter Greek alphabet.  If there were more than two dozen stars in the constellation that could be seen with the naked eye, then the Latin alphabet was used also.

       Bayer's system did have some flaws: what previous astronomers labeled at the right side of a constellation, he labeled as the left, and he bracketed star within the same constellation that had the same magnitude, but did not indicate how he chose the letters within the brackets.  This lead to confusion among astronomers, and there are still objections to some of the theories of how Bayer chose the letters.  Bayer's original designations are still in use today, in addition to further designated stars. Because of the advances in technology, more dim stars were able to be located and astronomers have named them with only Roman numerals and the numerals in combination with letters.  This lead to additions to Bayer's classification.

       Despite the confusion over the structure of the nomenclature of the stars, Johann Bayer aided the division of the celestial sphere.  He died in 1625 at the age of 53, Bayer's legacy still lives on.  His accomplishments in the field of astronomy were beneficial to the division and organization of the sky, and are still in practice today.