@article{13459,
  abstract     = {The B emission-line stars are rapid rotators that were probably spun up by mass and angular momentum accretion through mass transfer in an interacting binary. Mass transfer will strip the donor star of its envelope to create a small and hot subdwarf remnant. Here we report on Hubble Space Telescope/STIS far-ultraviolet spectroscopy of a sample of Be stars that reveals the presence of the hot sdO companion through the calculation of cross-correlation functions of the observed and model spectra. We clearly detect the spectral signature of the sdO star in 10 of the 13 stars in the sample, and the spectral signals indicate that the sdO stars are hot, relatively faint, and slowly rotating as predicted by models. A comparison of their temperatures and radii with evolutionary tracks indicates that the sdO stars occupy the relatively long-lived, He-core burning stage. Only 1 of the 10 detections was a known binary prior to this investigation, which emphasizes the difficulty of finding such Be+sdO binaries through optical spectroscopy. However, these results and others indicate that many Be stars probably host hot subdwarf companions.},
  author       = {Wang, Luqian and Gies, Douglas R. and Peters, Geraldine J. and Götberg, Ylva Louise Linsdotter and Chojnowski, S. Drew and Lester, Kathryn V. and Howell, Steve B.},
  issn         = {1538-3881},
  journal      = {The Astronomical Journal},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {5},
  publisher    = {American Astronomical Society},
  title        = {{The detection and characterization of Be+sdO binaries from HST/STIS FUV spectroscopy}},
  doi          = {10.3847/1538-3881/abf144},
  volume       = {161},
  year         = {2021},
}

@article{11604,
  abstract     = {The NASA Transiting Exoplanet Survey Satellite (TESS) is observing tens of millions of stars with time spans ranging from ∼27 days to about 1 yr of continuous observations. This vast amount of data contains a wealth of information for variability, exoplanet, and stellar astrophysics studies but requires a number of processing steps before it can be fully utilized. In order to efficiently process all the TESS data and make it available to the wider scientific community, the TESS Data for Asteroseismology working group, as part of the TESS Asteroseismic Science Consortium, has created an automated open-source processing pipeline to produce light curves corrected for systematics from the short- and long-cadence raw photometry data and to classify these according to stellar variability type. We will process all stars down to a TESS magnitude of 15. This paper is the next in a series detailing how the pipeline works. Here, we present our methodology for the automatic variability classification of TESS photometry using an ensemble of supervised learners that are combined into a metaclassifier. We successfully validate our method using a carefully constructed labeled sample of Kepler Q9 light curves with a 27.4 days time span mimicking single-sector TESS observations, on which we obtain an overall accuracy of 94.9%. We demonstrate that our methodology can successfully classify stars outside of our labeled sample by applying it to all ∼167,000 stars observed in Q9 of the Kepler space mission.},
  author       = {Audenaert, J. and Kuszlewicz, J. S. and Handberg, R. and Tkachenko, A. and Armstrong, D. J. and Hon, M. and Kgoadi, R. and Lund, M. N. and Bell, K. J. and Bugnet, Lisa Annabelle and Bowman, D. M. and Johnston, C. and García, R. A. and Stello, D. and Molnár, L. and Plachy, E. and Buzasi, D. and Aerts, C.},
  issn         = {1538-3881},
  journal      = {The Astronomical Journal},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {5},
  publisher    = {IOP Publishing},
  title        = {{TESS Data for Asteroseismology (T’DA) stellar variability classification pipeline: Setup and application to the Kepler Q9 data}},
  doi          = {10.3847/1538-3881/ac166a},
  volume       = {162},
  year         = {2021},
}

@article{11616,
  abstract     = {We present the discovery of HD 221416 b, the first transiting planet identified by the Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology of the host star is possible. HD 221416 b (HIP 116158, TOI-197) is a bright (V = 8.2 mag), spectroscopically classified subgiant that oscillates with an average frequency of about 430 μHz and displays a clear signature of mixed modes. The oscillation amplitude confirms that the redder TESS bandpass compared to Kepler has a small effect on the oscillations, supporting the expected yield of thousands of solar-like oscillators with TESS 2 minute cadence observations. Asteroseismic modeling yields a robust determination of the host star radius (R⋆ = 2.943 ± 0.064 R⊙), mass (M⋆ = 1.212 ± 0.074 M⊙), and age (4.9 ± 1.1 Gyr), and demonstrates that it has just started ascending the red-giant branch. Combining asteroseismology with transit modeling and radial-velocity observations, we show that the planet is a "hot Saturn" (Rp = 9.17 ± 0.33 R⊕) with an orbital period of ∼14.3 days, irradiance of F = 343 ± 24 F⊕, and moderate mass (Mp = 60.5 ± 5.7 M⊕) and density (ρp = 0.431 ± 0.062 g cm−3). The properties of HD 221416 b show that the host-star metallicity–planet mass correlation found in sub-Saturns (4–8 R⊕) does not extend to larger radii, indicating that planets in the transition between sub-Saturns and Jupiters follow a relatively narrow range of densities. With a density measured to ∼15%, HD 221416 b is one of the best characterized Saturn-size planets to date, augmenting the small number of known transiting planets around evolved stars and demonstrating the power of TESS to characterize exoplanets and their host stars using asteroseismology.},
  author       = {Huber, Daniel and Chaplin, William J. and Chontos, Ashley and Kjeldsen, Hans and Christensen-Dalsgaard, Jørgen and Bedding, Timothy R. and Ball, Warrick and Brahm, Rafael and Espinoza, Nestor and Henning, Thomas and Jordán, Andrés and Sarkis, Paula and Knudstrup, Emil and Albrecht, Simon and Grundahl, Frank and Andersen, Mads Fredslund and Pallé, Pere L. and Crossfield, Ian and Fulton, Benjamin and Howard, Andrew W. and Isaacson, Howard T. and Weiss, Lauren M. and Handberg, Rasmus and Lund, Mikkel N. and Serenelli, Aldo M. and Rørsted Mosumgaard, Jakob and Stokholm, Amalie and Bieryla, Allyson and Buchhave, Lars A. and Latham, David W. and Quinn, Samuel N. and Gaidos, Eric and Hirano, Teruyuki and Ricker, George R. and Vanderspek, Roland K. and Seager, Sara and Jenkins, Jon M. and Winn, Joshua N. and Antia, H. M. and Appourchaux, Thierry and Basu, Sarbani and Bell, Keaton J. and Benomar, Othman and Bonanno, Alfio and Buzasi, Derek L. and Campante, Tiago L. and Çelik Orhan, Z. and Corsaro, Enrico and Cunha, Margarida S. and Davies, Guy R. and Deheuvels, Sebastien and Grunblatt, Samuel K. and Hasanzadeh, Amir and Di Mauro, Maria Pia and A. García, Rafael and Gaulme, Patrick and Girardi, Léo and Guzik, Joyce A. and Hon, Marc and Jiang, Chen and Kallinger, Thomas and Kawaler, Steven D. and Kuszlewicz, James S. and Lebreton, Yveline and Li, Tanda and Lucas, Miles and Lundkvist, Mia S. and Mann, Andrew W. and Mathis, Stéphane and Mathur, Savita and Mazumdar, Anwesh and Metcalfe, Travis S. and Miglio, Andrea and F. G. Monteiro, Mário J. P. and Mosser, Benoit and Noll, Anthony and Nsamba, Benard and Joel Ong, Jia Mian and Örtel, S. and Pereira, Filipe and Ranadive, Pritesh and Régulo, Clara and Rodrigues, Thaíse S. and Roxburgh, Ian W. and Aguirre, Victor Silva and Smalley, Barry and Schofield, Mathew and Sousa, Sérgio G. and Stassun, Keivan G. and Stello, Dennis and Tayar, Jamie and White, Timothy R. and Verma, Kuldeep and Vrard, Mathieu and Yıldız, M. and Baker, David and Bazot, Michaël and Beichmann, Charles and Bergmann, Christoph and Bugnet, Lisa Annabelle and Cale, Bryson and Carlino, Roberto and Cartwright, Scott M. and Christiansen, Jessie L. and Ciardi, David R. and Creevey, Orlagh and Dittmann, Jason A. and Nascimento, Jose-Dias Do and Eylen, Vincent Van and Fürész, Gabor and Gagné, Jonathan and Gao, Peter and Gazeas, Kosmas and Giddens, Frank and Hall, Oliver J. and Hekker, Saskia and Ireland, Michael J. and Latouf, Natasha and LeBrun, Danny and Levine, Alan M. and Matzko, William and Natinsky, Eva and Page, Emma and Plavchan, Peter and Mansouri-Samani, Masoud and McCauliff, Sean and Mullally, Susan E. and Orenstein, Brendan and Soto, Aylin Garcia and Paegert, Martin and van Saders, Jennifer L. and Schnaible, Chloe and Soderblom, David R. and Szabó, Róbert and Tanner, Angelle and Tinney, C. G. and Teske, Johanna and Thomas, Alexandra and Trampedach, Regner and Wright, Duncan and Yuan, Thomas T. and Zohrabi, Farzaneh},
  issn         = {0004-6256},
  journal      = {The Astronomical Journal},
  keywords     = {Space and Planetary Science, Astronomy and Astrophysics},
  number       = {6},
  publisher    = {IOP Publishing},
  title        = {{A hot Saturn orbiting an oscillating late subgiant discovered by TESS}},
  doi          = {10.3847/1538-3881/ab1488},
  volume       = {157},
  year         = {2019},
}