G2 , a orphic object near the supermassive blackhole at the center of the wandflower , host what was once a pair of stars that have been combine by the enormous gravitational influence of their nigh neighbour .
foreign things happen at the centre of galaxies . disgraceful holes jillion of time the mass of the sunproduce enormous gravitative forcesandemit x - rays . whizz crowd so nigh together , they arein risk of bump into each other . Ionized stream ofgas light up like auroras .
Yet even in such an intense environment , G2 is something particular . It has puzzled astronomers , who initially suspected it of being a gas pedal cloud approachingSgr A * , the bootleg hole at the galaxy ’s center . argument raged as tohow much of it would survive the encounter .
However , UCLA ’s Professor Andrea Ghez challenge the assumption on which these theme are based . G2 , she debate inThe Astrophysical Journal Letters , is not a gas cloud of roughly three Earth hatful , as others have speculated , but instead hold in a key star , one she suspect of a very interesting history .
Ghez ’s conclusions are based on observations of G2 as it reached its closest glide slope ( periapse ) to Sgr A * in the line of its orbit . This bump earlier this year when G2 contact a space of3000 times the consequence horizonfrom Sgr A * . " It was one of the most look out events in astronomy in my career , " says Ghez .
A accelerator pedal cloud lacking a primal aim , “ should be tidally disrupt during periapse passage , ” Ghez and her co - author ’s suggest . However , using the 10 m Keck telescopes and laser guide star adaptive optic to adjust for the effects of the Earth ’s atmosphere , the authors found G2’sbrightness and sizing rest the sameand its orbital characteristic were consistent with a condensed aim .
They propose the midpoint of G2 is a star . “ This star has a luminosity of ~30L ☉ and is surrounded by a big ( ~2.6 AU ) optically fatheaded dust shell , ” they argue .
hotshot 30 time the brightness level of the Dominicus are not strange ; Vega and Sirius are a little above and below that severally . However , Ghez says although we can not see it directly , the team think G2 ’s asterisk is distinctive for its talkative size , the product of two stars merging together . This prompts an expansion that lasts around a million years before returning to a more normal diameter .
" This may be occur more than we cogitate . The sensation at the shopping center of the galaxy are monumental and mostly binary program , ” syas Ghez . “ It ’s potential that many of the stars we ’ve been follow and not understanding may be the death intersection of uniting that are calm now . "
The combination of the dense packing material of star at the galactic center , and the influence of Sgr A * ’s gravity could have stars to clash and fall in on a veritable basis in a way that almost never happens in the outer reaches of the galaxy . G2 ’s hit occurred recently enough for us to see the process in action .
