Two students have managed to map the entirety of the Milky Way, thanks to dwarf stars. They've taken a closer look at the sky and have now shown that there are a total of 58 billion dwarf stars in our galaxy.
The Milky Way galaxy consists of a flat disc that mostly has closely spaced bright stars. It also has a halo, a sphere of stars with a much lower density located around the disk.
But learning exactly what our Milky Way galaxy looks like is difficult work. This is largely because we reside within the galaxy, so we can't exactly get a clear picture of it from the outside. That's why astronomers have created maps of the stars in the night sky to get a better idea of what our galaxy is like. Now, though, two students have looked at dimmer stars.
Dwarf stars are undersized and often have too low of a mass to burn hydrogen. This means that they're best viewed with near-infrared cameras. In this latest study, the researchers looked at red dwarfs of spectral class M, which are particularly dim.
The researchers used three density models that astronomers use to describe the flat disc and halo, both separately and combined. Then, the students applied the Markov Chain Monte Carlo method. This is when you let a computer program test all possible values of each parameter of the model. Then, it fixes the value which corresponds best with the data.
In the end, the researchers were able to use these dwarfs to get a better look at our galaxy as a whole. The results could be huge for future research for the ESA's Euclid Space Telescope, which is due to be launched in 2020.
"With our research, astronomers can now better assess whether they are dealing with a distant galaxy or a star in our own galaxy," Dieuwertje van der Vlugt, one of the students who conducted the research, said.
Already, researchers are looking forward to findings from Euclid. It's likely that its observations could lead an even more accurate picture of the Milky Way. In addition, these latest findings will help with these new observations.
The findings are published in the May 2016 journal Monthly Notices of the Royal Astronomical Society.
