New Spectral 'Ruler' Can be Used by Astronomers to Measure the Stars for Gaia Project

Astronomers have a new way to measure the stars. They have created a new stellar scale as a type of "ruler" that they can use to investigate the atmospheric structure and chemical make-up of stars, making it far easier to classify and compare data on star discoveries.

In order to create this ruler, the researchers selected 34 initial "benchmark" stars in order to represent the different kinds of stellar populations in our galaxy. These consisted of hot stars, cold stars, red giants and dwarfs, as well as stars with different chemical patterns. This detailed range of information on the 34 stars formed the first value set for measuring the millions that scientists aim to catalogue.

"We took stars which had been measured a lot so the parameters are very well-known, but needed to be brought to the same scale for the new benchmark-essentially, using the stars we know most about to help measure the stars we know nothing about," said Paula Jofre, one of the researchers, in a news release. "In previous galactic studies, the sun is used as the standard to show a method is working, along with a few other well-known stars. But I chose this one because it works for my method, you choose a different one for different reasons; data may not match."

This new ruler is actually being used on some of the largest astronomy projects to date, including Gaia. Launched at the end of last year, the project will aim to gather data on over a billion stars in the Milky Way, which will allow astronomers to study stars and planetary systems in close detail for the first time. The new ruler will be needed to ensure that analysis of the data is done in the most effective and efficient way.

"Now this set of data scales for the benchmark stars can be used as a way of making definitive measurements of others stars-invaluable to a wide range of projects," said Jofre.

The findings are published in the journal Astronomy & Astrophysics.