We report the serendipitous discovery of a stellar stream in the constellation Pegasus in the south Galactic hemisphere .
The stellar stream was detected using the SDSS Data Release 14 by means of a matched filter in the color–magnitude diagram that is optimised for a stellar population that is 8 Gyr old with [ Fe/H ] = - 0.46 dex , and located at heliocentric distance of 18 kpc .
The candidate stream is faint ( turnoff point at r _ { 0 } \sim 19.6 ) , sparse and barely visible in SDSS photometry .
It is also detected in the ( shallower ) Pan-STARRs data .
The residual stellar density in the ( u - g ) _ { 0 } , ( g - r ) _ { 0 } color–color diagram gives the same estimate for the age and [ Fe/H ] of this stellar population .
The stream is located at a Galactic coordinates ( l,b ) = ( 79. \degr 4 , -24. \degr 6 ) and extends over 9 ^ { \circ } ( 2.5 kpc ) , with a width of 112 pc .
The narrow width suggests a globular cluster progenitor .