The same way we need values to measure everything from temperature to time, astronomers have now developed a new stellar scale as a “ruler” to help them classify and compare data on star discoveries.
Previously, as with the longitude problem 300 years earlier for fixing locations on earth, there was no unified system of reference for calibrating the heavens.
The astronomers selected 34 initial ‘benchmark’ stars to represent the different kinds of stellar populations in our galaxy, such as hot stars, cold stars, red giants and dwarfs, as well as stars that cover the different chemical patterns – or “metallicity” in their spectrum, as this is the “cosmic clock” which allows astronomers to read a star’s age.
This detailed range of information on the 34 stars form the first value set for measuring the millions of stars that the Gaia satellite, an unmanned space observatory of the European Space Agency, aims to catalogue.
