  We report the discovery of two short-period massive giant planets from NASA's
Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC
207110080) and TOI-559 (TIC 209459275), were identified from the 30-minute
cadence Full Frame Images and confirmed using ground-based photometric and
spectroscopic follow-up observations from TESS's Follow-up Observing Program
Working Group. We find that TOI-558 b, which transits an F-dwarf
($M_{\star}=1.349^{+0.064}_{-0.065}\ M_{\odot}$,
$R_{\star}=1.496^{+0.042}_{-0.040}\ R_{\odot}$, $T_{eff}=6466^{+95}_{-93}$ K,
age $1.79^{+0.91}_{-0.73}$ Gyr) with an orbital period of 14.574 days, has a
mass of $3.61\pm0.15\ M_J$, a radius of $1.086^{+0.041}_{-0.038}\ R_J$, and an
eccentric (e=$0.300^{+0.022}_{-0.020}$) orbit. TOI-559 b transits a G-dwarf
($M_{\star}=1.026\pm0.057\ M_{\odot}$, $R_{\star}=1.233^{+0.028}_{-0.026}\
R_{\odot}$, $T_{eff}=5925^{+85}_{-76}$ K, age $1.79^{+0.91}_{-0.73}$ Gyr) in an
eccentric (e=$0.151\pm0.011$) 6.984-day orbit with a mass of
$6.01^{+0.24}_{-0.23}\ M_J$ and a radius of $1.091^{+0.028}_{-0.025}\ R_J$. Our
spectroscopic follow-up also reveals a long-term radial velocity trend for
TOI-559, indicating a long-period companion. The statistically significant
orbital eccentricity measured for each system suggests that these planets
migrated to their current location through dynamical interactions.
Interestingly, both planets are also massive ($>3\ M_J$), adding to the
population of massive hot Jupiters identified by TESS. Prompted by these new
detections of high-mass planets, we analyzed the known mass distribution of hot
Jupiters but find no significant evidence for multiple populations. TESS should
provide a near magnitude-limited sample of transiting hot Jupiters, allowing
for future detailed population studies.
