Astronomers have discovered that the Milky Way’s outer region, which is represented by the stellar halo, contains a group of stars that are almost as distant as halfway to a neighbouring galaxy.
According to the researchers, these 208 stars are located in the most remote reaches of the Milky Way’s stellar halo, which is made up of spherical stellar clouds that are filled with dark matter. The furthest of these stars is almost a million light years away. Light year refers to the distance that light travels in a year, Reuters reported.
The stars, which were spotted by the Canada-France–Hawaii Telescope, are part of a group of stars known as the RR Lyrae, which are characterized by their low mass and low abundance of elements. One of the distant stars has a mass of around 70% of that of the sun. Milky Way’s other stars are not known to be as distant.
Based on their observations, the researchers from the University of California, Santa Cruz concluded that these distant stars originated from regions within dwarf galaxies and were eventually merged with the Milky Way. These distant stars are the remnants of the Milky Way’s gravitationally shredded host galaxies. They were left behind as the cosmic debris from the merger event, they determined.
The study author and UC Santa Cruz’s chair of astronomy and astrophysics., Raja Guhathakurta further illustrated that larger galaxy grows by eating smaller galaxies – by eating their own kind,
The Milky Way galaxy, which is about 26,000 light years away from Earth, is filled with around 100 billion to 400 billion stars. One of its spiral arms contains our sun. Around 5% of the galaxy’s stars can be found in its stellar halo. Dark matter contributes to most of the universe’s mass and its huge gravity that makes visible matter unite and form stars and galaxies is responsible for the basic structure of the halo.
The newly discovered stars are located in the Milky Way’s poorly understood outer region, which is about half the distance from the Andromeda galaxy.
According to GuhaThakurta, each of the outer halo stars could possibly have planets similar to the Earth and other planets orbiting the Sun in the Milky Way.