Why do most stars never form alone?

All About Space - - Harpercollins -

it is be­lieved that maybe up to 50 per cent of all stars are in bi­nary sys­tems, with many re­searchers even sug­gest­ing that an even higher per­cent­age of stars are born as bi­na­ries.

the high per­cent­age of bi­nary stars is closely linked to the way stars form. it is well es­tab­lished that most stars form in clus­ters rather than in iso­la­tion. in the dense parts of clus­ters such stars could pair up, form­ing bi­nary stars. an­other way that bi­na­ries can form is by the break­ing up of discs around newly formed stars. these discs are a nat­u­ral re­sult of the star­for­ma­tion process due to the ini­tial ro­ta­tion of the in­ter­stel­lar cloud that col­lapses to form a star. a disc in­creases in mass as more ma­te­rial from the cloud falls onto it and can be­come un­sta­ble or, in other words, it be­comes too heavy to be main­tained and frag­ments, break­ing up into stars.

if frag­men­ta­tion hap­pens quickly af­ter the first star has formed then the two stars may end up hav­ing sim­i­lar masses. if it hap­pens later on, the re­sult will be a bi­nary with two stars with un­equal masses. the for­ma­tion of more mul­ti­ple star sys­tems – triples, quadru­ples and so on – is also pos­si­ble, and quite com­mon. the study of bi­na­ries is im­por­tant as their

prop­er­ties con­tain in­for­ma­tion about how stars form.

Dr Dim­itris Sta­matel­los is a guild re­search fel­low of As­tro­physics at the Jeremiah Hor­rocks In­sti­tute, Uni­ver­sity of Cen­tral Lancs

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.