one thousand million of years ago a small beetleweed plunged through the Milky Way and out the other side . The ripples it create get an tremendous eruption of star formation . While we have no way yet to be sure if our own Sun was the result of this galactic intervention , the timing looks correct .
TheSagittarius gnome galaxy(Sgr ) is among the closest galaxies to our own milklike Way . However , it was only discovered in the 1990s , being both pocket-size and , from our location , hidden behind the dense stars of the center of the Milky Way .
Once thought too small to make much difference , there is increasing recognition Sgr ’s movement create wavelet in the Milky Way ’s gas cloud that stimulate atomization and the geological formation of pocket dense enough to become stars .
“ It is experience from be mannequin that Sagittarius settle into the Milky Way three time – first about 5 or 6 billion years ago , then about 2 billion years ago , and finally 1 billion years ago,”Dr Tomás Ruiz - Laraof the Instituto de Astrofísica de Canarias , Spain say in astatement .
Dr Ruiz - Lara has taken vantage of the wealth of info the European Space Agency’sGaia satellitehas provided on wiz ' bowel movement and composition to report the timing of major salvo of star constitution inNature Astronomy .
“ We found three full stop of increased virtuoso formation that peaked 5.7 billion year ago , 1.9 billion year ago , and 1 billion years ago , fit with the time when Sagittarius is believed to have passed through the disk of the Milky Way , ” Ruiz - Larasaid .
As another paper in the same edition reported , the passage of a galaxy through a expectant one can destroy the entire bodily structure , leaving a " ring of fire " behind . Sgr ’s size and angle of impact made for something much less dramatic .
Ruiz - Lara ’s teampreviously showedthe amalgamation between the Milky Way and another beetleweed set off a dramatic period of star formation . However , this had pass by the time of the first Sgr encounter , with the galaxy a still home in between
“ The Sun formed at the clip when stars were imprint in the Milky Way because of the first passageway of Sagittarius,”saidco - authorDr Carrme Gallart . “ We do n’t acknowledge if the particular swarm of gas and junk that turn over into the Sun collapsed because of the effects of Sagittarius or not . But it is a possible scenario . "
Sagittarius miss some of its wad in every encounter with its large neighbor , do each passage less influential than the last . The first starburst lasted 2 billion long time to include the Sun ’s giving birth , but the others were much shorter . The authors think a humble explosion of wizard shaping in the last 70 million age may be the result of Sgr making a fourth passage through the Milky Way , but this meter it carried so little material the effects are severe to detect .
