Astronomers Chart 219 Million Stars in the Milky Way Galaxy with New Map

Scientists have made new strides when it comes to cataloguing the stars in our Milky Way galaxy. They've found that no fewer than 219 million stars are located in our home galaxy, revealing a bit more about the features of the Milky Way.

The Milky Way appears as a glowing band that stretches across the sky. To astronomers, though, this is the disk of our own galaxy, a system which stretches across 100,000 light-years. The disk contains the majority of the stars in the galaxy, including the sun, in addition to the densiest concentrations of dust and gas.

Over the past ten years, researchers have used the Isaac Newton Telescope (INT) on La Palma in the Canary Islands in order to assemble the catalogue. The 2.5-m mirror of the INT allowed the scientists to resolve and chart a total of 219 million separate stars that were brighter than the 20^th magnitude.

The researchers didn't just catalogue the stars, though; they also created a map of the disk of the galaxy. This new map reveals how the density of the stars varies and gives the researchers new insight into the structure of this system of stars, gas and dust.

Now that the catalogue is released, the researchers are offering the public free access to measurements taken through two broad band filters capturing light at the red end of the visible spectrum, and in a narrow band capturing the brightest hydrogen emission line, H-alpha. This actually enables imaging of the nebulae found in the greatest number within the disk of the Milky Way.

The findings are published in the Monthly Notices of the Royal Astronomical Society.