According to a forecast made by a team of astronomers announced at the meeting of the American Astronomical Society in Honolulu, the star V Sagittae (V Sge) located in the constellation of the Arrow (Sagitta) should “explode” around the year 2083, during which time it will become brighter than Sirius, currently the brightest star in our skies, and one of the brightest stars in the entire Milky Way.
V Sge is actually a binary system consisting of an ordinary star that orbits around a white dwarf and gives its material to the latter. Astronomers predict that during the next decades the system will start to light up more and more and more quickly until, just around the year 2083, the rate of growth of the white dwarf will reach a limit point. The ordinary star will pour more and more material on the white dwarf until all its mass will fall on it creating a sort of huge wind that will spread outwards and that will increase the brightness of the system by a lot.
The system will become brighter than Sirius and perhaps even more than Venus, as Bradley E. Schaefer, professor of the Department of Physics and Astronomy at Louisiana State University and one of the authors of the study, explains. V Sge is part of a class of binary stars called “variable cataclysmic stars” or “cataclysmic variables.” These binary systems consist of an ordinary star orbiting a white dwarf. Usually, the white dwarf is more massive than the ordinary star but in the case of V Sge we are faced with a system where the orbiting star is at least 3.9 times more massive than the white dwarf.
The system is getting brighter and brighter: since 1907 the brightness has multiplied by a factor of 10x. The brightness rate is parallel to the amount of material that the star is giving to the white dwarf but of course all this will come to an end, in 2083 according to astronomers’ calculations, the point of final fusion during which the mass of the star will release a huge amount of gravitational energy emitting a stellar wind like never seen before and raising the brightness of the system to a level slightly smaller than that of a supernova.
This very bright star can be seen in the sky for about a month, an event that will be historic at an astronomical level since something so bright in the sky was last seen only in 1604 with Kepler’s supernova (SN 1604), the explosion of a star located in the constellation Ophiuchus and 20,000 light years away from us that was visible to the naked eye for 18 months.