Discovery of an Edge-on Circumstellar Debris Disk Around
  BD+45$^{\circ}$598: a Newly Identifed Member of the $\beta$ Pictoris Moving
  Group
  We report the discovery of a circumstellar debris disk viewed nearly edge-on
and associated with the young, K1 star BD+45$^{\circ}$598 using high-contrast
imaging at 2.2$\mu$m obtained at the W.M.~Keck Observatory. We detect the disk
in scattered light with a peak significance of $\sim$5$\sigma$ over three
epochs, and our best-fit model of the disk is an almost edge-on $\sim$70 AU
ring, with inclination angle $\sim$87$^\circ$. Using the NOEMA interferometer
at the Plateau de Bure Observatory operating at 1.3mm, we find resolved
continuum emission aligned with the ring structure seen in the 2.2$\mu$m
images. We estimate a fractional infrared luminosity of $L_{IR}/L_{tot}$
$\simeq6^{+2}_{-1}$$\times$$10^{-4}$, higher than that of the debris disk
around AU Mic. Several characteristics of BD+45$^{\circ}$598, such as its
galactic space motion, placement in a color-magnitude diagram, and strong
presence of Lithium, are all consistent with its membership in the $\beta$
Pictoris Moving Group with an age of 23$\pm$3 Myr. However, the galactic
position for BD+45$^{\circ}$598 is slightly discrepant from previously-known
members of the $\beta$ Pictoris Moving Group, possibly indicating an extension
of members of this moving group to distances of at least 70pc.
BD+45$^{\circ}$598 appears to be an example from a population of young
circumstellar debris systems associated with newly identified members of young
moving groups that can be imaged in scattered light, key objects for mapping
out the early evolution of planetary systems from $\sim$10-100 Myr. This target
will also be ideal for northern-hemisphere, high-contrast imaging platforms to
search for self-luminous, planetary mass companions residing in this system.
