Abstract: | We report the discovery of two short-period Saturn-mass planets, one
transiting the G subgiant TOI-954 (TIC 44792534, $ V = 10.343 $, $ T = 9.78 $)
observed in TESS Sectors 4 & 5, and one transiting the G dwarf EPIC 246193072
($ V = 12.70 $, $ K = 10.67 $) observed in K2 Campaigns 12 & 19. We confirm and
characterize these two planets with a variety of ground-based archival and
follow-up observations, including photometry, reconnaissance spectroscopy,
precise radial velocity, and high-resolution imaging. Combining all available
data, we find that TOI-954 b has a radius of $0.852_{-0.062}^{+0.053} ,
R_{mathrm{J}}$ and a mass of $0.174_{-0.017}^{+0.018} , M_{mathrm{J}}$ and
is in a 3.68 d orbit, while EPIC 246193072 b has a radius of
$0.774_{-0.024}^{+0.026} , R_{mathrm{J}}$ and a mass of
$0.260_{-0.022}^{+0.020} , M_{mathrm{J}}$ and is in a 12.46 d orbit. As
TOI-954 b is 30 times more irradiated than EPIC 246193072 b but is more or less
of the same size, these two planets provide an opportunity to test whether
irradiation leads to inflation of Saturn-mass planets and contribute to future
comparative studies that explore Saturn-mass planets at contrasting points in
their lifetimes. |