  The Kepler mission showed us that planets with sizes between that of Earth
and Neptune appear to be the most common type in our Galaxy. These
"super-Earths" continue to be of great interest for exoplanet formation,
evolution, and composition studies. However, the number of super-Earths with
well-constrained mass and radius measurements remains small (40 planets with
$\sigma_{\rm{mass}}<$ 25\%), due in part to the faintness of their host stars
causing ground-based mass measurements to be challenging. Recently, three
transiting super-Earth planets were detected by the K2 mission around the
nearby star GJ 9827/HIP 115752, at only 30 pc away. The radii of the planets
span the "radius gap"' detected by Fulton et al. (2017), and all orbit within
~6.5 days, easing follow-up observations. Here we report radial velocity (RV)
observations of GJ 9827, taken between 2010 and 2016 with the Planet Finder
Spectrograph on the Magellan II Telescope. We employ two different RV analysis
packages, SYSTEMIC and RadVel, to derive masses and thus densities of the GJ
9827 planets. We also test a Gaussian Process regression analysis, but find the
correlated stellar noise is not well constrained by the PFS data, and that the
GP tends to over fit the RV semi-amplitudes resulting in a lower K value. Our
RV observations are not able to place strong mass constraints on the two outer
planets (c & d) but do indicate that planet b, at 1.64 R$_{\oplus}$ and ~8
M$_{\oplus}$, is one of the most massive (and dense) super-Earth planets
detected to date.
