Edge of the Milky Way
January 10, 2023 - Astronomers have discovered over 200 stars that form the Milky Way's edge in the stellar halo component of our galaxy – halfway to the Andromeda galaxy.
Using data from the Next Generation Virgo Cluster Survey they were able to detect 208 distant variable stars called RR Lyrae - old stars that because of their physical structure brighten and dim in a regular cycle of between 5 and 24 hours.
Because RR Lyrae have a uniform average brightness, it was possible to calculate the distance of the furthest star at around 1.04 million light years from the centre of the Milky Way, almost halfway to the Andromeda galaxy which is 2.5 million light years.
(1 light year = 9.461 trillion km)