The European Space Agency ’s Gaia mission is conducting some unbelievable observations of the Milky Way , provide unexampled insight into the many champion we can see in the sky . And , it turns out , it can also tell us more about the stars that we ca n’t see .
As reported inAstronomy & Astrophysics , Gaia spot a upstage whiz around 49,000 light - years out suddenly brightening and dimming . Then , after a few week , it brighten and dim again . The event , cognise as Gaia16aye , was utterly peculiar . The dimming happened within one mean solar day , something no other supernova or star has been known to do .
It turn out that the sensation was n’t doing anything . The change in luminosity was due to two other asterisk locate much closer to Earth , roughly 2,500 light - years forth . These are too dull to be seeable but their gravity , thanks to their alignment in the sky , acted as a electron lens , changing the brightness of the more distant object .
Microlensing , as this phenomenon is known , is often used in astronomy to study the invisible , such as gloomy matter or black holes . This is the 2d microlensing event discover by Gaia , but it really mystify the researchers as it did n’t look at all like the previous case .
“ If you have a single lens , because of a single object , there would be just a low , firm rising slope in smartness and then there would be a smooth decline as the lens pass in front of the upstage source and then move forth , ” lead author Łukasz Wyrzykowski , from the Astronomical Observatory at the University of Warsaw , Poland , say in astatement .
“ In this case , not only did the star brightness level send away sharply rather than smoothly , but after a duet of workweek it brightened up again , which is very unusual . Over the 500 days of observation , we have view it clear up up and refuse five times . ”
The effective explanation for the peculiarities is that it was not just one star microlensing , but two . The team take in enough info to be able to tell that the two stars are cherry dwarfs 0.57 and 0.36 times the stack of our Sun , severally . Their space is about twice the distance between the Earth and the Sun and they orbit the common center of mass in 2.88 years .
“ We do n’t see this binary system at all , but from only seeing the effects that it create by acting as a crystalline lens on a background star , we were able-bodied to tell everything about it , ” add carbon monoxide - writer Przemek Mróz , a postdoctoral scholar at the California Institute of Technology .
The written report was potential thanks to follow - up observations from 50 dissimilar observation tower worldwide , allowing for uninterrupted monitoring of this special issue .
