We report the kinematic discovery of the Pisces Stellar Stream ( PSS ) , at Galactic longitude l \approx 135 ^ { \circ } and -39 ^ { \circ } < b < -36 ^ { \circ } .
We originally identified this halo substructure from velocities of red giant branch stars in Sloan Digital Sky Survey ( SDSS ) Data Release 8 , and confirmed its presence in turnoff stars from SDSS photometric data .
The PSS is a narrow , kinematically cold tidal stream , with \sigma _ { v, 0 } \approx 8 km s ^ { -1 } .
Its metallicity is [ Fe/H ] \approx - 2.2 , with \sim 0.3 -dex dispersion .
The color-magnitude signature of the stream turnoff , combined with our measured metallicity , places the PSS at a distance of 35 \pm 3 kpc .
The Pisces Stellar Stream is the same as the previously announced “ Triangulum stream ” and part of the proposed “ stream a ” .
We rule out an association of the PSS with other previously known Milky Way substructures in the same region of the sky .