<P> Circa 1600, the names of the constellations were used to name the stars in the corresponding regions of the sky . The German astronomer Johann Bayer created a series of star maps and applied Greek letters as designations to the stars in each constellation . Later a numbering system based on the star's right ascension was invented and added to John Flamsteed's star catalogue in his book "Historia coelestis Britannica" (the 1712 edition), whereby this numbering system came to be called Flamsteed designation or Flamsteed numbering . </P> <P> The only internationally recognized authority for naming celestial bodies is the International Astronomical Union (IAU). The International Astronomical Union maintains the Working Group on Star Names (WGSN) which catalogs and standardizes proper names for stars . A number of private companies sell names of stars, which the British Library calls an unregulated commercial enterprise . The IAU has disassociated itself from this commercial practice, and these names are neither recognized by the IAU, professional astronomers, nor the amateur astronomy community . One such star - naming company is the International Star Registry, which, during the 1980s, was accused of deceptive practice for making it appear that the assigned name was official . This now - discontinued ISR practice was informally labeled a scam and a fraud, and the New York City Department of Consumer Affairs issued a violation against ISR for engaging in a deceptive trade practice . </P> <P> Although stellar parameters can be expressed in SI units or CGS units, it is often most convenient to express mass, luminosity, and radii in solar units, based on the characteristics of the Sun . In 2015, the IAU defined a set of nominal solar values (defined as SI constants, without uncertainties) which can be used for quoting stellar parameters: </P> <Dl> <Dd> <Table> <Tr> <Td> nominal solar luminosity: </Td> <Td> L = 3.828 × 10 W </Td> </Tr> <Tr> <Td> nominal solar radius </Td> <Td> R = 6.957 × 10 m </Td> </Tr> </Table> </Dd> </Dl>

Characteristics of stars based on the characteristics of the sun