A mysterious streak of stars coursing through space like a vast, cosmic river has astronomers conflicted. Is it the result of a "renegade" black hole surging through space, or is it a bizarrely flat galaxy in disguise? New research makes the case for the latter – but the mystery is far from settled.
The cosmic streak was initially detected by NASA's Hubble Space Telescope and estimated to measure 200,000 light-years long, or about twice the diameter of the Milky Way. Last month, a study published in The Astrophysical Journal Letters posited that the streak might be the result of a runaway supermassive black hole plowing through a cloud of stellar gas and dust roughly 7.5 billion light-years from Earth.
