Mysterious radio signal in the Milky Way brightens and fades over decades, baffling astronomers
Object VT J1906+0849, located 49,000 light-years away, shows behavior unlike any known transient, possibly a black hole or neutron star accreting material
A strange radio signal from the outskirts of the Milky Way has astronomers puzzled: the object, designated VT J1906+0849, has been brightening and fading over decades, with its radio spectrum shifting in ways that do not match any known celestial phenomenon. The source, located at least 49,000 light-years from Earth beyond the Norma-Cygnus spiral arm, was first noticed as a bright radio transient in 2017 data from the Very Large Array Sky Survey, but subsequent analysis of older observations revealed it had been active since at least 2005, with no trace in 1996. The findings are published in the Astrophysical Journal.