  (3200) Phaethon is a compelling object as it has an asteroidal appearance and
spectrum, produces a weak dust tail during perihelion at just 0.14 AU, and is
the parent body of the Geminid Meteor Shower. A better understanding of the
physical properties of Phaethon is needed to understand the nature of its
current and previous activity, relationship to potential source populations,
and to plan for the upcoming flyby of the DESTINY+ spacecraft of Phaethon in
the 2020s. We performed rotationally-resolved spectroscopy of Phaethon at
visible and near-infrared wavelengths (0.4-2.5 microns) in 2007 and 2017,
respectively, to better understand its surface properties. The visible and
near-infrared observations both spanned nearly a full rotation or more and were
under similar observing geometries, covering the whole surface with the
exception of the north pole. The visible wavelengths show blue slopes with only
minor slope variations and no absorption features. The NIR data is minimally
varying and concave upwards, from very blue to blue-neutral with increasing
wavelength. We fit the short-wavelength tail of Phaethon's thermal emission and
retrieve an average visible albedo of pv = 0.08 +/- 0.01, which is lower than
previous measurements but plausible in light of the recent larger
radar-measured diameter of Phaethon. We retrieve an average infrared beaming
parameter of Phaethon of eta = 1.70 +/- 0.05, which is similar to previous
results. We discuss the implications of Phaethon's visible and near-infrared
spectrum as well as the lower albedo on its origin, source population, and
evolutionary history.
