Researchers from the National Astronomical Observatory of Japan (NAOJ) and the University of Tokyo used Subaru's Suprime-Cam camera to discover an unusual streak of ionized hydrogen gas associated with a galaxy 300 million light-years from Earth. The filament of gas is only 6 thousand light-years wide, yet extends 200,000 light-years, about the distance between the Milky Way Galaxy and its companion, the Large Magellanic Cloud. Finding such an extremely narrow and long ionized gas cloud is a first in astronomy.

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More info: Subaru telescope web page