The Magellan-TESS Survey I: Survey Description and Mid-Survey Results. (arXiv:2011.11560v1 [astro-ph.EP])

The Magellan-TESS Survey I: Survey Description and Mid-Survey Results. (arXiv:2011.11560v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Teske_J/0/1/0/all/0/1">Johanna Teske</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_S/0/1/0/all/0/1">Sharon Xuesong Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wolfgang_A/0/1/0/all/0/1">Angie Wolfgang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gan_T/0/1/0/all/0/1">Tianjun Gan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Plotnykov_M/0/1/0/all/0/1">Mykhaylo Plotnykov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Armstrong_D/0/1/0/all/0/1">David J. Armstrong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Butler_R/0/1/0/all/0/1">R. Paul Butler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cale_B/0/1/0/all/0/1">Bryson Cale</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crane_J/0/1/0/all/0/1">Jeffrey D. Crane</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Howard_W/0/1/0/all/0/1">Ward Howard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jensen_E/0/1/0/all/0/1">Eric L. N. Jensen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Law_N/0/1/0/all/0/1">Nicholas Law</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shectman_S/0/1/0/all/0/1">Stephen A. Shectman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Plavchan_P/0/1/0/all/0/1">Peter Plavchan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valencia_D/0/1/0/all/0/1">Diana Valencia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vanderburg_A/0/1/0/all/0/1">Andrew Vanderburg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ricker_G/0/1/0/all/0/1">George Ricker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vanderspek_R/0/1/0/all/0/1">Roland Vanderspek</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Latham_D/0/1/0/all/0/1">Dave W. Latham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Seager_S/0/1/0/all/0/1">Sara Seager</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Winn_J/0/1/0/all/0/1">Joshua W. Winn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jenkins_J/0/1/0/all/0/1">Jon M. Jenkins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Adibekyan_V/0/1/0/all/0/1">Vardan Adibekyan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barrado_D/0/1/0/all/0/1">David Barrado</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barros_S/0/1/0/all/0/1">Susana C. C. Barros</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_D/0/1/0/all/0/1">David J. A. Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bryant_E/0/1/0/all/0/1">Edward M. Bryant</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burt_J/0/1/0/all/0/1">Jennifer Burt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Caldwell_D/0/1/0/all/0/1">Douglas A. Caldwell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charbonneau_D/0/1/0/all/0/1">David Charbonneau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cloutier_R/0/1/0/all/0/1">Ryan Cloutier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Collins_K/0/1/0/all/0/1">Karen A. Collins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Collins_K/0/1/0/all/0/1">Kevin I. Collins</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Colon_N/0/1/0/all/0/1">Nicole D. Colon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Conti_D/0/1/0/all/0/1">Dennis M. Conti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Demangeon_O/0/1/0/all/0/1">Olivier D. S. Demangeon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eastman_J/0/1/0/all/0/1">Jason D. Eastman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Elmufti_M/0/1/0/all/0/1">Mohammed Elmufti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feng_F/0/1/0/all/0/1">Fabo Feng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Flowers_E/0/1/0/all/0/1">Erin Flowers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Guerrero_N/0/1/0/all/0/1">Natalia M. Guerrero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hojjatpanah_S/0/1/0/all/0/1">Saeed Hojjatpanah</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Irwin_J/0/1/0/all/0/1">Jonathan M. Irwin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Isopi_G/0/1/0/all/0/1">Giovanni Isopi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lillo_Box_J/0/1/0/all/0/1">Jorge Lillo-Box</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mallia_F/0/1/0/all/0/1">Franco Mallia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Massey_B/0/1/0/all/0/1">Bob Massey</a>, et al. (22 additional authors not shown)

One of the most significant revelations from Kepler is that roughly one-third
of Sun-like stars host planets which orbit their stars within 100 days and are
between the size of Earth and Neptune. How do these super-Earth and sub-Neptune
planets form, what are they made of, and do they represent a continuous
population or naturally divide into separate groups? Measuring their masses and
thus bulk densities can help address these questions of their origin and
composition. To that end, we began the Magellan-TESS Survey (MTS), which uses
Magellan II/PFS to obtain radial velocity (RV) masses of 30 transiting
exoplanets discovered by TESS and develops an analysis framework that connects
observed planet distributions to underlying populations. In the past, RV
measurements of small planets have been challenging to obtain due to the
faintness and low RV semi-amplitudes of most Kepler systems, and challenging to
interpret due to the potential biases in the existing ensemble of small planet
masses from non-algorithmic decisions for target selection and observation
plans. The MTS attempts to minimize these biases by focusing on bright TESS
targets and employing a quantitative selection function and multi-year
observing strategy. In this paper, we (1) describe the motivation and survey
strategy behind the MTS, (2) present our first catalog of planet mass and
density constraints for 25 TESS Objects of Interest (TOIs; 20 in our population
analysis sample, five that are members of the same systems), and (3) employ a
hierarchical Bayesian model to produce preliminary constraints on the
mass-radius (M-R) relation. We find qualitative agreement with prior
mass-radius relations but some quantitative differences (abridged). The the
results of this work can inform more detailed studies of individual systems and
offer a framework that can be applied to future RV surveys with the goal of
population inferences.

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