Tails from the Orphanage
  Examining a portion of the northern Sloan Digital Sky Survey (SDSS)
footprint, we detect at least three and possibly seven halo debris streams. One
of these (PS1-D) was recently detected in the Pan-STARRS1 $3\pi$ survey, and
the remaining two are also evident as extensions of the SDSS detections. All of
these streams are metal poor and are found at a distance of around $21 \pm 5$
kpc. The streams are between 65\arcdeg~ and 70\arcdeg~ in length, oriented
almost north-south, and are nearly parallel and somewhat convergent with the
neighboring Orphan stream. Surface densities ranging from 1.5 to 0.5 stars per
square degree down to $g = 21.7$ correspond to surface brightnesses between 35
and 37 mag per square arcsecond. The streams each appear to be more than 300 pc
across, suggesting either dwarf/ultrafaint galaxy progenitors or long-term
heating of very ancient globular cluster streams. The orbits of all but one of
these streams appear to be nearly radial, and the orbit normals suggest that
all of the streams are part of the Vast Polar Structure, a relatively narrow
plane that contains most of the known satellite galaxies, globular clusters,
and stellar streams.
