@article{11619,
  abstract     = {We report on the confirmation and mass determination of π Men c, the first transiting planet discovered by NASA’s TESS space mission. π Men is a naked-eye (V = 5.65 mag), quiet G0 V star that was previously known to host a sub-stellar companion (π Men b) on a longperiod (Porb = 2091 days), eccentric (e = 0.64) orbit. Using TESS time-series photometry, combined with Gaia data, published UCLES at AAT Doppler measurements, and archival HARPS at ESO-3.6m radial velocities, we found that π Men c is a close-in planet with an orbital period of Porb = 6.27 days, a mass of Mc = 4.52 ± 0.81 M⊕, and a radius of Rc = 2.06 ± 0.03 R⊕. Based on the planet’s orbital period and size, π Men c is a super-Earth located at, or close to, the radius gap, while its mass and bulk density suggest it may have held on to a significant atmosphere. Because of the brightness of the host star, this system is highly suitable for a wide range of further studies to characterize the planetary atmosphere and dynamical properties. We also performed an asteroseismic analysis of the TESS data and detected a hint of power excess consistent with the seismic values expected for this star, although this result depends on the photometric aperture used to extract the light curve. This marginal detection is expected from pre-launch simulations hinting at the asteroseismic potential of the TESS mission for longer, multi-sector observations and/or for more evolved bright stars.},
  author       = {Gandolfi, D. and Barragán, O. and Livingston, J. H. and Fridlund, M. and Justesen, A. B. and Redfield, S. and Fossati, L. and Mathur, S. and Grziwa, S. and Cabrera, J. and García, R. A. and Persson, C. M. and Van Eylen, V. and Hatzes, A. P. and Hidalgo, D. and Albrecht, S. and Bugnet, Lisa Annabelle and Cochran, W. D. and Csizmadia, Sz. and Deeg, H. and Eigmüller, Ph. and Endl, M. and Erikson, A. and Esposito, M. and Guenther, E. and Korth, J. and Luque, R. and Montañes Rodríguez, P. and Nespral, D. and Nowak, G. and Pätzold, M. and Prieto-Arranz, J.},
  issn         = {1432-0746},
  journal      = {Astronomy & Astrophysics},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, planetary systems / planets and satellites, detection / planets and satellites, fundamental parameters / planets and satellites, terrestrial planets / stars, fundamental parameters},
  publisher    = {EDP Sciences},
  title        = {{TESS’s first planet: A super-Earth transiting the naked-eye star π Mensae}},
  doi          = {10.1051/0004-6361/201834289},
  volume       = {619},
  year         = {2018},
}

@article{11620,
  abstract     = {We report the discovery and characterization of HD 89345b (K2-234b; EPIC 248777106b), a Saturn-sized planet orbiting a slightly evolved star. HD 89345 is a bright star (V = 9.3 mag) observed by the K2 mission with 1 min time sampling. It exhibits solar-like oscillations. We conducted asteroseismology to determine the parameters of the star, finding the mass and radius to be 1.12+0.04−0.01M⊙ and 1.657+0.020−0.004R⊙⁠, respectively. The star appears to have recently left the main sequence, based on the inferred age, 9.4+0.4−1.3Gyr⁠, and the non-detection of mixed modes. The star hosts a ‘warm Saturn’ (P = 11.8 d, Rp = 6.86 ± 0.14 R⊕). Radial-velocity follow-up observations performed with the FIbre-fed Echelle Spectrograph, HARPS, and HARPS-N spectrographs show that the planet has a mass of 35.7 ± 3.3 M⊕. The data also show that the planet’s orbit is eccentric (e ≈ 0.2). An investigation of the rotational splitting of the oscillation frequencies of the star yields no conclusive evidence on the stellar inclination angle. We further obtained Rossiter–McLaughlin observations, which result in a broad posterior of the stellar obliquity. The planet seems to confirm to the same patterns that have been observed for other sub-Saturns regarding planet mass and multiplicity, orbital eccentricity, and stellar metallicity.},
  author       = {Van Eylen, V and Dai, F and Mathur, S and Gandolfi, D and Albrecht, S and Fridlund, M and García, R A and Guenther, E and Hjorth, M and Justesen, A B and Livingston, J and Lund, M N and Pérez Hernández, F and Prieto-Arranz, J and Regulo, C and Bugnet, Lisa Annabelle and Everett, M E and Hirano, T and Nespral, D and Nowak, G and Palle, E and Silva Aguirre, V and Trifonov, T and Winn, J N and Barragán, O and Beck, P G and Chaplin, W J and Cochran, W D and Csizmadia, S and Deeg, H and Endl, M and Heeren, P and Grziwa, S and Hatzes, A P and Hidalgo, D and Korth, J and Mathis, S and Montañes Rodriguez, P and Narita, N and Patzold, M and Persson, C M and Rodler, F and Smith, A M S},
  issn         = {1365-2966},
  journal      = {Monthly Notices of the Royal Astronomical Society},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics, asteroseismology, planets and satellites: composition, planets and satellites: formation, planets and satellites: fundamental parameters},
  number       = {4},
  pages        = {4866--4880},
  publisher    = {Oxford University Press},
  title        = {{HD 89345: A bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2}},
  doi          = {10.1093/mnras/sty1390},
  volume       = {478},
  year         = {2018},
}