Edge of the Milky Way
January 10, 2023 - Os astrónomos descobriram mais de 200 estrelas que formam o limiar da Via Láctea estão a mais de um milhão de anos luz, quase a meio caminho da galáxia vizinha Andrómeda.
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)