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1. The PLATO Mission

Author

Rauer, Heike, Aerts, Conny, Cabrera, Juan, Deleuil, Magali, Erikson, Anders, Gizon, Laurent, Goupil, Mariejo, Heras, Ana, Lorenzo-Alvarez, Jose, Marliani, Filippo, Martin-Garcia, Cesar, Mas-Hesse, J. Miguel, O'Rourke, Laurence, Osborn, Hugh, Pagano, Isabella, Piotto, Giampaolo, Pollacco, Don, Ragazzoni, Roberto, Ramsay, Gavin, Udry, Stéphane, Appourchaux, Thierry, Benz, Willy, Brandeker, Alexis, Güdel, Manuel, Janot-Pacheco, Eduardo, Kabath, Petr, Kjeldsen, Hans, Min, Michiel, Santos, Nuno, Smith, Alan, Suarez, Juan-Carlos, Werner, Stephanie C., Aboudan, Alessio, Abreu, Manuel, Acuña, Lorena, Adams, Moritz, Adibekyan, Vardan, Affer, Laura, Agneray, François, Agnor, Craig, Børsen-Koch, Victor Aguirre, Ahmed, Saad, Aigrain, Suzanne, Al-Bahlawan, Ashraf, Gil, M de los Angeles Alcacera, Alei, Eleonora, Alencar, Silvia, Alexander, Richard, Alfonso-Garzón, Julia, Alibert, Yann, Prieto, Carlos Allende, Almeida, Leonardo, Sobrino, Roi Alonso, Altavilla, Giuseppe, Althaus, Christian, Trujillo, Luis Alonso Alvarez, Amarsi, Anish, Eiff, Matthias Ammler-von, Amôres, Eduardo, Andrade, Laerte, Antoniadis-Karnavas, Alexandros, António, Carlos, del Moral, Beatriz Aparicio, Appolloni, Matteo, Arena, Claudio, Armstrong, David, Aliaga, Jose Aroca, Asplund, Martin, Audenaert, Jeroen, Auricchio, Natalia, Avelino, Pedro, Baeke, Ann, Baillié, Kevin, Balado, Ana, Balestra, Andrea, Ball, Warrick, Ballans, Herve, Ballot, Jerome, Barban, Caroline, Barbary, Gaële, Barbieri, Mauro, Forteza, Sebastià Barceló, Barker, Adrian, Barklem, Paul, Barnes, Sydney, Navascues, David Barrado, Barragan, Oscar, Baruteau, Clément, Basu, Sarbani, Baudin, Frederic, Baumeister, Philipp, Bayliss, Daniel, Bazot, Michael, Beck, Paul G., Bedding, Tim, Belkacem, Kevin, Bellinger, Earl, Benatti, Serena, Benomar, Othman, Bérard, Diane, Bergemann, Maria, Bergomi, Maria, Bernardo, Pierre, Biazzo, Katia, Bignamini, Andrea, Bigot, Lionel, Billot, Nicolas, Binet, Martin, Biondi, David, Biondi, Federico, Birch, Aaron C., Bitsch, Bertram, Ceballos, Paz Victoria Bluhm, Bódi, Attila, Bognár, Zsófia, Boisse, Isabelle, Bolmont, Emeline, Bonanno, Alfio, Bonavita, Mariangela, Bonfanti, Andrea, Bonfils, Xavier, Bonito, Rosaria, Bonomo, Aldo Stefano, Börner, Anko, Saikia, Sudeshna Boro, Martín, Elisa Borreguero, Borsa, Francesco, Borsato, Luca, Bossini, Diego, Bouchy, Francois, Boué, Gwenaël, Boufleur, Rodrigo, Boumier, Patrick, Bourrier, Vincent, Bowman, Dominic M., Bozzo, Enrico, Bradley, Louisa, Bray, John, Bressan, Alessandro, Breton, Sylvain, Brienza, Daniele, Brito, Ana, Brogi, Matteo, Brown, Beverly, Brown, David, Brun, Allan Sacha, Bruno, Giovanni, Bruns, Michael, Buchhave, Lars A., Bugnet, Lisa, Buldgen, Gaël, Burgess, Patrick, Busatta, Andrea, Busso, Giorgia, Buzasi, Derek, Caballero, José A., Cabral, Alexandre, Calderone, Flavia, Cameron, Robert, Cameron, Andrew, Campante, Tiago, Martins, Bruno Leonardo Canto, Cara, Christophe, Carone, Ludmila, Carrasco, Josep Manel, Casagrande, Luca, Casewell, Sarah L., Cassisi, Santi, Castellani, Marco, Castro, Matthieu, Catala, Claude, Fernández, Irene Catalán, Catelan, Márcio, Cegla, Heather, Cerruti, Chiara, Cessa, Virginie, Chadid, Merieme, Chaplin, William, Charpinet, Stephane, Chiappini, Cristina, Chiarucci, Simone, Chiavassa, Andrea, Chinellato, Simonetta, Chirulli, Giovanni, Christensen-Dalsgaard, Jorgen, Church, Ross, Claret, Antonio, Clarke, Cathie, Claudi, Riccardo, Clermont, Lionel, Coelho, Hugo, Coelho, Joao, Cogato, Fabrizio, Colomé, Josep, Condamin, Mathieu, Conseil, Simon, Corbard, Thierry, Correia, Alexandre C. M., Corsaro, Enrico, Cosentino, Rosario, Costes, Jean, Cottinelli, Andrea, Covone, Giovanni, Creevey, Orlagh L., Crida, Aurelien, Csizmadia, Szilard, Cunha, Margarida, Curry, Patrick, da Costa, Jefferson, da Silva, Francys, Dalal, Shweta, Damasso, Mario, Damiani, Cilia, Damiani, Francesco, Chagas, Maria Liduina das, Davies, Melvyn, Davies, Guy, Davies, Ben, Davison, Gary, de Almeida, Leandro, de Angeli, Francesca, de Barros, Susana Cristina Cabral, Leão, Izan de Castro, de Freitas, Daniel Brito, de Freitas, Marcia Cristina, De Martino, Domitilla, de Medeiros, José Renan, de Paula, Luiz Alberto, de Plaa, Jelle, De Ridder, Joris, Deal, Morgan, Decin, Leen, Deeg, Hans, Degl'Innocenti, Scilla, Deheuvels, Sebastien, del Burgo, Carlos, Del Sordo, Fabio, Delgado-Mena, Elisa, Demangeon, Olivier, Denk, Tilmann, Derekas, Aliz, Desidera, Silvano, Dexet, Marc, Di Criscienzo, Marcella, Di Giorgio, Anna Maria, Di Mauro, Maria Pia, Rial, Federico Jose Diaz, Díaz-García, José-Javier, Dima, Marco, Dinuzzi, Giacomo, Dionatos, Odysseas, Distefano, Elisa, Nascimento Jr., Jose-Dias do, Domingo, Albert, D'Orazi, Valentina, Dorn, Caroline, Doyle, Lauren, Duarte, Elena, Ducellier, Florent, Dumaye, Luc, Dumusque, Xavier, Dupret, Marc-Antoine, Eggenberger, Patrick, Ehrenreich, David, Eigmüller, Philipp, Eising, Johannes, Emilio, Marcelo, Eriksson, Kjell, Ermocida, Marco, Giribaldi, Riano Isidoro Escate, Eschen, Yoshi, Estrela, Inês, Evans, Dafydd Wyn, Fabbian, Damian, Fabrizio, Michele, Faria, João Pedro, Farina, Maria, Farinato, Jacopo, Feliz, Dax, Feltzing, Sofia, Fenouillet, Thomas, Ferrari, Lorenza, Ferraz-Mello, Sylvio, Fialho, Fabio, Fienga, Agnes, Figueira, Pedro, Fiori, Laura, Flaccomio, Ettore, Focardi, Mauro, Foley, Steve, Fontignie, Jean, Ford, Dominic, Fornazier, Karin, Forveille, Thierry, Fossati, Luca, Franca, Rodrigo de Marca, da Silva, Lucas Franco, Frasca, Antonio, Fridlund, Malcolm, Furlan, Marco, Gabler, Sarah-Maria, Gaido, Marco, Gallagher, Andrew, Galli, Emanuele, Garcia, Rafael A., Hernández, Antonio García, Munoz, Antonio Garcia, García-Vázquez, Hugo, Haba, Rafael Garrido, Gaulme, Patrick, Gauthier, Nicolas, Gehan, Charlotte, Gent, Matthew, Georgieva, Iskra, Ghigo, Mauro, Giana, Edoardo, Gill, Samuel, Girardi, Leo, Winter, Silvia Giuliatti, Giusi, Giovanni, da Silva, João Gomes, Zazo, Luis Jorge Gómez, Gomez-Lopez, Juan Manuel, Hernández, Jonay Isai González, Murillo, Kevin Gonzalez, Gorius, Nicolas, Gouel, Pierre-Vincent, Goulty, Duncan, Granata, Valentina, Grenfell, John Lee, Grießbach, Denis, Grolleau, Emmanuel, Grouffal, Salomé, Grziwa, Sascha, Guarcello, Mario Giuseppe, Gueguen, Loïc, Guenther, Eike Wolf, Guilhem, Terrasa, Guillerot, Lucas, Guiot, Pierre, Guterman, Pascal, Gutiérrez, Antonio, Gutiérrez-Canales, Fernando, Hagelberg, Janis, Haldemann, Jonas, Hall, Cassandra, Handberg, Rasmus, Harrison, Ian, Harrison, Diana L., Hasiba, Johann, Haswell, Carole A., Hatalova, Petra, Hatzes, Artie, Haywood, Raphaelle, Hébrard, Guillaume, Heckes, Frank, Heiter, Ulrike, Hekker, Saskia, Heller, René, Helling, Christiane, Helminiak, Krzysztof, Hemsley, Simon, Heng, Kevin, Hermans, Aline, Hermes, JJ, Torres, Nadia Hidalgo, Hinkel, Natalie, Hobbs, David, Hodgkin, Simon, Hofmann, Karl, Hojjatpanah, Saeed, Houdek, Günter, Huber, Daniel, Huesler, Joseph, Hui-Bon-Hoa, Alain, Huygen, Rik, Huynh, Duc-Dat, Iro, Nicolas, Irwin, Jonathan, Irwin, Mike, Izidoro, André, Jacquinod, Sophie, Jannsen, Nicholas Emborg, Janson, Markus, Jeszenszky, Harald, Jiang, Chen, Mancebo, Antonio José Jimenez, Jofre, Paula, Johansen, Anders, Johnston, Cole, Jones, Geraint, Kallinger, Thomas, Kálmán, Szilárd, Kanitz, Thomas, Karjalainen, Marie, Karjalainen, Raine, Karoff, Christoffer, Kawaler, Steven, Kawata, Daisuke, Keereman, Arnoud, Keiderling, David, Kennedy, Tom, Kenworthy, Matthew, Kerschbaum, Franz, Kidger, Mark, Kiefer, Flavien, Kintziger, Christian, Kislyakova, Kristina, Kiss, László, Klagyivik, Peter, Klahr, Hubert, Klevas, Jonas, Kochukhov, Oleg, Köhler, Ulrich, Kolb, Ulrich, Koncz, Alexander, Korth, Judith, Kostogryz, Nadiia, Kovács, Gábor, Kovács, József, Kozhura, Oleg, Krivova, Natalie, Kučinskas, Arunas, Kuhlemann, Ilyas, Kupka, Friedrich, Laauwen, Wouter, Labiano, Alvaro, Lagarde, Nadege, Laget, Philippe, Laky, Gunter, Lam, Kristine Wai Fun, Lambrechts, Michiel, Lammer, Helmut, Lanza, Antonino Francesco, Lanzafame, Alessandro, Martiz, Mariel Lares, Laskar, Jacques, Latter, Henrik, Lavanant, Tony, Lawrenson, Alastair, Lazzoni, Cecilia, Lebre, Agnes, Lebreton, Yveline, Etangs, Alain Lecavelier des, Leinhardt, Zoe, Leleu, Adrien, Lendl, Monika, Leto, Giuseppe, Levillain, Yves, Libert, Anne-Sophie, Lichtenberg, Tim, Ligi, Roxanne, Lignieres, Francois, Lillo-Box, Jorge, Linsky, Jeffrey, Liu, John Scige, Loidolt, Dominik, Longval, Yuying, Lopes, Ilídio, Lorenzani, Andrea, Ludwig, Hans-Guenter, Lund, Mikkel, Lundkvist, Mia Sloth, Luri, Xavier, Maceroni, Carla, Madden, Sean, Madhusudhan, Nikku, Maggio, Antonio, Magliano, Christian, Magrin, Demetrio, Mahy, Laurent, Maibaum, Olaf, Malac-Allain, LeeRoy, Malapert, Jean-Christophe, Malavolta, Luca, Maldonado, Jesus, Mamonova, Elena, Manchon, Louis, Mann, Andrew, Mantovan, Giacomo, Marafatto, Luca, Marconi, Marcella, Mardling, Rosemary, Marigo, Paola, Marinoni, Silvia, Marques, Érico, Marques, Joao Pedro, Marrese, Paola Maria, Marshall, Douglas, Perales, Silvia Martínez, Mary, David, Marzari, Francesco, Masana, Eduard, Mascher, Andrina, Mathis, Stéphane, Mathur, Savita, Figueiredo, Ana Carolina Mattiuci, Maxted, Pierre F. L., Mazeh, Tsevi, Mazevet, Stephane, Mazzei, Francesco, McCormac, James, McMillan, Paul, Menou, Lucas, Merle, Thibault, Meru, Farzana, Mesa, Dino, Messina, Sergio, Mészáros, Szabolcs, Meunier, Nadége, Meunier, Jean-Charles, Micela, Giuseppina, Michaelis, Harald, Michel, Eric, Michielsen, Mathias, Michtchenko, Tatiana, Miglio, Andrea, Miguel, Yamila, Milligan, David, Mirouh, Giovanni, Mitchell, Morgan, Moedas, Nuno, Molendini, Francesca, Molnár, László, Mombarg, Joey, Montalban, Josefina, Montalto, Marco, Monteiro, Mário J. P. F. G., Morales, Juan Carlos, Morales-Calderon, Maria, Morbidelli, Alessandro, Mordasini, Christoph, Moreau, Chrystel, Morel, Thierry, Morello, Guiseppe, Morin, Julien, Mortier, Annelies, Mosser, Benoît, Mourard, Denis, Mousis, Olivier, Moutou, Claire, Mowlavi, Nami, Moya, Andrés, Muehlmann, Prisca, Muirhead, Philip, Munari, Matteo, Musella, Ilaria, Mustill, Alexander James, Nardetto, Nicolas, Nardiello, Domenico, Narita, Norio, Nascimbeni, Valerio, Nash, Anna, Neiner, Coralie, Nelson, Richard P., Nettelmann, Nadine, Nicolini, Gianalfredo, Nielsen, Martin, Niemi, Sami-Matias, Noack, Lena, Noels-Grotsch, Arlette, Noll, Anthony, Norazman, Azib, Norton, Andrew J., Nsamba, Benard, Ofir, Aviv, Ogilvie, Gordon, Olander, Terese, Olivetto, Christian, Olofsson, Göran, Ong, Joel, Ortolani, Sergio, Oshagh, Mahmoudreza, Ottacher, Harald, Ottensamer, Roland, Ouazzani, Rhita-Maria, Paardekooper, Sijme-Jan, Pace, Emanuele, Pajas, Miriam, Palacios, Ana, Palandri, Gaelle, Palle, Enric, Paproth, Carsten, Parro, Vanderlei, Parviainen, Hannu, Granado, Javier Pascual, Passegger, Vera Maria, Pastor-Morales, Carmen, Pätzold, Martin, Pedersen, May Gade, Hidalgo, David Pena, Pepe, Francesco, Pereira, Filipe, Persson, Carina M., Pertenais, Martin, Peter, Gisbert, Petit, Antoine C., Petit, Pascal, Pezzuto, Stefano, Pichierri, Gabriele, Pietrinferni, Adriano, Pinheiro, Fernando, Pinsonneault, Marc, Plachy, Emese, Plasson, Philippe, Plez, Bertrand, Poppenhaeger, Katja, Poretti, Ennio, Portaluri, Elisa, Portell, Jordi, de Mello, Gustavo Frederico Porto, Poyatos, Julien, Pozuelos, Francisco J., Moroni, Pier Giorgio Prada, Pricopi, Dumitru, Prisinzano, Loredana, Quade, Matthias, Quirrenbach160, ndreas, Reina6, Julio Arturo Rabanal, Soares, Maria Cristina Rabello, Raimondo, Gabriella, Rainer, Monica, Rodón, Jose Ramón, Ramón-Ballesta, Alejandro, Zapata, Gonzalo Ramos, Rätz, Stefanie, Rauterberg, Christoph, Redman, Bob, Redmer, Ronald, Reese, Daniel, Regibo, Sara, Reiners, Ansgar, Reinhold, Timo, Renie, Christian, Ribas, Ignasi, Ribeiro, Sergio, Ricciardi, Thiago Pereira, Rice, Ken, Richard, Olivier, Riello, Marco, Rieutord, Michel, Ripepi, Vincenzo, Rixon, Guy, Rockstein, Steve, Rodríguez, María Teresa Rodrigo, Díaz, Luisa Fernanda Rodríguez, Garcia, Juan Pablo Rodriguez, Rodriguez-Gomez, Julio, Roehlly, Yannick, Roig, Fernando, Rojas-Ayala, Bárbara, Rolf, Tobias, Rørsted, Jakob Lysgaard, Rosado, Hugo, Rosotti, Giovanni, Roth, Olivier, Roth, Markus, Rousseau, Alex, Roxburgh, Ian, Roy, Fabrice, Royer, Pierre, Ruane, Kirk, Mastropasqua, Sergio Rufini, de Galarreta, Claudia Ruiz, Russi, Andrea, Saar, Steven, Saillenfest, Melaine, Salaris, Maurizio, Salmon, Sebastien, Saltas, Ippocratis, Samadi, Réza, Samadi, Aunia, Samra, Dominic, da Silva, Tiago Sanches, Carrasco, Miguel Andrés Sánchez, Santerne, Alexandre, Santoli, Francesco, Santos, Ângela R. G., Mesa, Rosario Sanz, Sarro, Luis Manuel, Scandariato, Gaetano, Schäfer, Martin, Schlafly, Edward, Schmider, François-Xavier, Schneider, Jean, Schou, Jesper, Schunker, Hannah, Schwarzkopf, Gabriel Jörg, Serenelli, Aldo, Seynaeve, Dries, Shan, Yutong, Shapiro, Alexander, Shipman, Russel, Sicilia, Daniela, Sanmartin, Maria Angeles Sierra, Sigot, Axelle, Silliman, Kyle, Silvotti, Roberto, Simon, Attila E., Napoli, Ricardo Simoyama, Skarka, Marek, Smalley, Barry, Smiljanic, Rodolfo, Smit, Samuel, Smith, Alexis, Smith, Leigh, Snellen, Ignas, Sódor, Ádám, Sohl, Frank, Solanki, Sami K., Sortino, Francesca, Sousa, Sérgio, Southworth, John, Souto, Diogo, Sozzetti, Alessandro, Stamatellos, Dimitris, Stassun, Keivan, Steller, Manfred, Stello, Dennis, Stelzer, Beate, Stiebeler, Ulrike, Stokholm, Amalie, Storelvmo, Trude, Strassmeier, Klaus, Strøm, Paul Anthony, Strugarek, Antoine, Sulis, Sophia, Švanda, Michal, Szabados, László, Szabó, Róbert, Szabó, Gyula M., Szuszkiewicz, Ewa, Talens, Geert Jan, Teti, Daniele, Theisen, Tom, Thévenin, Frédéric, Thoul, Anne, Tiphene, Didier, Titz-Weider, Ruth, Tkachenko, Andrew, Tomecki, Daniel, Tonfat, Jorge, Tosi, Nicola, Trampedach, Regner, Traven, Gregor, Triaud, Amaury, Trønnes, Reidar, Tsantaki, Maria, Tschentscher, Matthias, Turin, Arnaud, Tvaruzka, Adam, Ulmer, Bernd, Ulmer-Moll, Solène, Ulusoy, Ceren, Umbriaco, Gabriele, Valencia, Diana, Valentini, Marica, Valio, Adriana, Guijarro, Ángel Luis Valverde, Van Eylen, Vincent, Van Grootel, Valerie, van Kempen, Tim A., Van Reeth, Timothy, Van Zelst, Iris, Vandenbussche, Bart, Vasiliou, Konstantinos, Vasilyev, Valeriy, de Mascarenhas, David Vaz, Vazan, Allona, Nunez, Marina Vela, Velloso, Eduardo Nunes, Ventura, Rita, Ventura, Paolo, Venturini, Julia, Trallero, Isabel Vera, Veras, Dimitri, Verdugo, Eva, Verma, Kuldeep, Vibert, Didier, Martinez, Tobias Vicanek, Vida, Krisztián, Vigan, Arthur, Villacorta, Antonio, Villaver, Eva, Aparicio, Marcos Villaverde, Viotto, Valentina, Vorobyov, Eduard, Vorontsov, Sergey, Wagner, Frank W., Walloschek, Thomas, Walton, Nicholas, Walton, Dave, Wang, Haiyang, Waters, Rens, Watson, Christopher, Wedemeyer, Sven, Weeks, Angharad, Weingril, Jörg, Weiss, Annita, Wendler, Belinda, West, Richard, Westerdorff, Karsten, Westphal, Pierre-Amaury, Wheatley, Peter, White, Tim, Whittaker, Amadou, Wickhusen, Kai, Wilson, Thomas, Windsor, James, Winter, Othon, Winther, Mark Lykke, Winton, Alistair, Witteck, Ulrike, Witzke, Veronika, Woitke, Peter, Wolter, David, Wuchterl, Günther, Wyatt, Mark, Yang, Dan, Yu, Jie, Sanchez, Ricardo Zanmar, Osorio, María Rosa Zapatero, Zechmeister, Mathias, Zhou, Yixiao, Ziemke, Claas, and Zwintz, Konstanze

Subjects
Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2 R_(Earth)) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5 %, 10 %, 10 % for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO's target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile at the beginning of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.

Published
2024

2. Angular momentum transport near convective-core boundaries of Gamma Doradus stars

Author

Moyano, Facundo, Eggenberger, Patrick, and Salmon, Sébastien

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Recent asteroseismic studies have revealed that the convective core of $\gamma$ Doradus stars rotates faster than their radiative interior. We study the development of differential rotation near the convective core to test angular momentum transport processes that are typically adopted in stellar evolution models. Models that only include the advection of angular momentum by meridional circulation and shear instabilities cannot reproduce current rotational constraints, irrespective of the initial conditions. The latest formulation of internal magnetic fields based on the Tayler instability is indeed able to reproduce the internal rotation rate of post-main sequence stars, however, it appears too efficient during the main sequence and has thus been disfavoured. A less efficient version of the same transport process can simultaneously reproduce the rotation rate of the convective core, the rotation rate in radiative regions as probed by gravity-modes, and the surface rotational velocities of $\gamma$ Doradus stars. Our work suggests that there are additional physical processes apart from internal magnetic fields at work in the stellar interiors of post-main sequence stars., Comment: Accepted for publication in Astronomy & Astrophysics. 5 pages, 7 figures

Published
2024
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3. TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf

Author

Hawthorn, Faith, Bayliss, Daniel, Wilson, Thomas G., Bonfanti, Andrea, Adibekyan, Vardan, Alibert, Yann, Sousa, Sérgio G., Collins, Karen A., Bryant, Edward M., Osborn, Ares, Armstrong, David J., Abe, Lyu, Acton, Jack S., Addison, Brett C., Agabi, Karim, Alonso, Roi, Alves, Douglas R., Anglada-Escudé, Guillem, Bárczy, Tamas, Barclay, Thomas, Barrado, David, Barros, Susana C. C., Baumjohann, Wolfgang, Bendjoya, Philippe, Benz, Willy, Bieryla, Allyson, Bonfils, Xavier, Bouchy, François, Brandeker, Alexis, Broeg, Christopher, Brown, David J. A., Burleigh, Matthew R., Buttu, Marco, Cabrera, Juan, Caldwell, Douglas A., Casewell, Sarah L., Charbonneau, David, Charnoz, Sébastian, Cloutier, Ryan, Cameron, Andrew Collier, Collins, Kevin I., Conti, Dennis M., Crouzet, Nicolas, Czismadia, Szilárd, Davies, Melvyn B., Deleuil, Magali, Delgado-Mena, Elisa, Delrez, Laetitia, Demangeon, Olivier D. S., Demory, Brice-Olivier, Dransfield, Georgina, Dumusque, Xavier, Egger, Jo Ann, Ehrenreich, David, Eigmüller, Philipp, Erickson, Anders, Essack, Zahra, Fortier, Andrea, Fossati, Luca, Fridlund, Malcolm, Günther, Maximilian N., Güdel, Manuel, Gandolfi, Davide, Gillard, Harvey, Gillon, Michaël, Gnilka, Crystal, Goad, Michael R., Goeke, Robert F., Guillot, Tristan, Hadjigeorghiou, Andreas, Hellier, Coel, Henderson, Beth A., Heng, Kevin, Hooton, Matthew J., Horne, Keith, Howell, Steve B., Hoyer, Sergio, Irwin, Jonathan M., Jenkins, James S., Jenkins, Jon M., Jensen, Eric L. N., Kane, Stephen R., Kendall, Alicia, Kielkopf, John F., Kiss, Laszlo L., Lacedelli, Gaia, Laskar, Jacques, Latham, David W., Etangs, Alain Lecavalier des, Leleu, Adrien, Lendl, Monika, Lillo-Box, Jorge, Lovis, Christophe, Mékarnia, Djamel, Massey, Bob, Masters, Tamzin, Maxted, Pierre F. L., Nascimbeni, Valerio, Nielsen, Louise D., O'Brien, Sean M., Olofsson, Göran, Osborn, Hugh P., Pagano, Isabella, Pallé, Enric, Persson, Carina M., Piotto, Giampaolo, Plavchan, Peter, Pollacco, Don, Queloz, Didier, Ragazzoni, Roberto, Rauer, Heike, Ribas, Ignasi, Ricker, George, Ségransan, Damien, Salmon, Sébastien, Santerne, Alexandre, Santos, Nuno C., Scandariato, Gaetano, Schmider, François-Xavier, Schwarz, Richard P., Seager, Sara, Shporer, Avi, Simon, Attila E., Smith, Alexis M. S., Srdoc, Gregor, Steller, Manfred, Suarez, Olga, Szabó, Gyula M., Teske, Johanna, Thomas, Nicolas, Tilbrook, Rosanna H., Triaud, Amaury H. M. J., Udry, Stéphane, Van Grootel, Valérie, Walton, Nicholas, Wang, Sharon X., Wheatley, Peter J., Winn, Joshua N., Wittenmyer, Robert A., and Zhang, Hui

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright ($T = 8.5$ mag), high proper motion ($\sim\,200$ mas yr$^{-1}$), low metallicity ([Fe/H]$\approx\,-0.28$) K-dwarf with a mass of $0.68\pm0.05$ M$_{\odot}$ and a radius of $0.67\pm0.01$ R$_{\odot}$. We obtain photometric follow-up observations with a variety of facilities, and we use these data-sets to determine that the inner planet, TOI-836 b, is a $1.70\pm0.07$ R$_{\oplus}$ super-Earth in a 3.82 day orbit, placing it directly within the so-called 'radius valley'. The outer planet, TOI-836 c, is a $2.59\pm0.09$ R$_{\oplus}$ mini-Neptune in an 8.60 day orbit. Radial velocity measurements reveal that TOI-836 b has a mass of $4.5\pm0.9$ M$_{\oplus}$ , while TOI-836 c has a mass of $9.6\pm2.6$ M$_{\oplus}$. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 minutes for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet.

Published
2022
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4. Backtracing the internal rotation history of the $\beta$ Cep star HD 129929

Author

Salmon, Sébastien, Moyano, Facundo, Eggenberger, Patrick, Haemmerlé, Lionel, and Buldgen, Gaël

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

HD 129929 is a slowly-rotating $\beta$ Cephei pulsator with a rich spectrum of detected oscillations, including two rotational multiplets. The asteroseismic interpretation revealed the presence of radial differential rotation in this massive star of $\sim$9.35 M . The stellar core is indeed estimated to spin $\sim$3.6 times faster than the surface. The surface rotation was consequently derived as $\sim$2 km/s. This massive star represents an ideal counter-part to the wealth of space-based photometry results for main-sequence and evolved low-mass stars. Those latter have revealed a new, and often unexpected, picture of the angular momentum transport processes acting in stellar interiors. We investigate in a new way the constraints on the internal rotation of HD 129929, focusing on their interpretation for the evolution of the internal rotation during the main sequence of a massive star. We test separately hydrodynamic and magnetic instability transport processes of angular momentum. We used the best asteroseismic model obtained in an earlier work. We calibrated stellar models including rotation, with different transport processes, to reproduce that reference model. We then looked whether one process is favoured to reproduce the rotation profile of HD 129929, based on the fit of the asteroseismic multiplets. The impact of the Tayler magnetic instability on the angular momentum transport predicts a ratio of the core-to-surface rotation rate of only 1.6, while the recently revised prescription of this mechanism predicts solid-body rotation. Both are too low in comparison with the asteroseismic inference. The models with only hydrodynamic processes are in good agreement with the asteroseismic measurements. Strikingly, we can also get a constraint on the profile of rotation on the zero age main sequence: likely, the ratio between the core and surface rotation was at least $\sim$1.7., Comment: 5 pages, 3 figures, accepted for publication as a letter in A&A

Published
2022
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5. Uncovering the true periods of the young sub-Neptunes orbiting TOI-2076

Author

Osborn, Hugh P., Bonfanti, Andrea, Gandolfi, Davide, Hedges, Christina, Leleu, Adrien, Fortier, Andrea, Futyan, David, Gutermann, Pascal, Maxted, Pierre F. L., Borsato, Luca, Collins, Karen A., da Silva, J. Gomes, Chew, Yilen Gómez Maqueo, Hooton, Matthew J., Lendl, Monika, Parviainen, Hannu, Salmon, Sébastien, Schanche, Nicole, Serrano, Luisa M., Sousa, Sergio G., Tuson, Amy, Ulmer-Moll, Solène, Van Grootel, Valerie, Wells, R. D., Wilson, Thomas G., Alibert, Yann, Alonso, Roi, Anglada, Guillem, Asquier, Joel, Navascues, David Barrado y, Baumjohann, Wolfgang, Beck, Thomas, Benz, Willy, Biondi, Federico, Bonfils, Xavier, Bouchy, Francois, Brandeker, Alexis, Broeg, Christopher, Bárczy, Tamas, Barros, S. C. C., Cabrera, Juan, Charnoz, Sébastien, Cameron, Andrew Collier, Csizmadia, Szilard, Davies, Melvyn B., Deleuil, Magali, Delrez, Laetitia, Demory, Brice-Olivier, Ehrenreich, David, Erikson, Anders, Fossati, Luca, Fridlund, Malcolm, Gillon, Michaël, Gómez-Muñoz, M. A., Güdel, Manuel, Heng, Kevin, Hoyer, Sergio, Isaak, Kate G., Kiss, Laszlo, Laskar, Jacques, Etangs, Alain Lecavelier des, Lovis, Christophe, Magrin, Demetrio, Malavolta, Luca, McCormac, James, Nascimbeni, Valerio, Olofsson, Göran, Ottensamer, Roland, Pagano, Isabella, Pallé, Enric, Peter, Gisbert, Piazza, Daniele, Piotto, Giampaolo, Pollacco, Don, Queloz, Didier, Ragazzoni, Roberto, Rando, Nicola, Rauer, Heike, Reimers, Christian, Ribas, Ignasi, Demangeon, Olivier D. S., Smith, Alexis M. S., Sabin, L., Santos, Nuno, Scandariato, Gaetano, Schroffenegger, U., Schwarz, Rick P., Shporer, Avi, Simon, Attila E., Steller, Manfred, Szabó, Gyula M., Ségransan, Damien, Thomas, Nicolas, Udry, Stéphane, Walter, Ingo, and Walton, Nicholas

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Context: TOI-2076 is a transiting three-planet system of sub-Neptunes orbiting a bright (G = 8.9 mag), young ($340\pm80$ Myr) K-type star. Although a validated planetary system, the orbits of the two outer planets were unconstrained as only two non-consecutive transits were seen in TESS photometry. This left 11 and 7 possible period aliases for each. Aims: To reveal the true orbits of these two long-period planets, precise photometry targeted on the highest-probability period aliases is required. Long-term monitoring of transits in multi-planet systems can also help constrain planetary masses through TTV measurements. Methods: We used the MonoTools package to determine which aliases to follow, and then performed space-based and ground-based photometric follow-up of TOI-2076 c and d with CHEOPS, SAINT-EX, and LCO telescopes. Results: CHEOPS observations revealed a clear detection for TOI-2076 c at $P=21.01538^{+0.00084}_{-0.00074}$ d, and allowed us to rule out three of the most likely period aliases for TOI-2076 d. Ground-based photometry further enabled us to rule out remaining aliases and confirm the $P=35.12537\pm0.00067$ d alias. These observations also improved the radius precision of all three sub-Neptunes to $2.518\pm0.036$, $3.497\pm0.043$, and $3.232\pm0.063$ $R_\oplus$. Our observations also revealed a clear anti-correlated TTV signal between planets b and c likely caused by their proximity to the 2:1 resonance, while planets c and d appear close to a 5:3 period commensurability, although model degeneracy meant we were unable to retrieve robust TTV masses. Their inflated radii, likely due to extended H-He atmospheres, combined with low insolation makes all three planets excellent candidates for future comparative transmission spectroscopy with JWST., Comment: 18 pages, 7 figure, 8 tables. Accepted for publication in Astronomy & Astrophysics. Photometry available on CDS/Vizier. Python package presented for modelling duotransiting planet candidates available at https://github.com/hposborn/MonoTools. Modelling & figure-creation code available at https://github.com/hposborn/TOI2076

Published
2022
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6. Grids of stellar models with rotation VI: Models from 0.8 to 120 $M_\odot$ at a metallicity Z = 0.006

Author

Eggenberger, Patrick, Ekström, Sylvia, Georgy, Cyril, Martinet, Sébastien, Pezzotti, Camilla, Nandal, Devesh, Meynet, Georges, Buldgen, Gaël, Salmon, Sébastien, Haemmerlé, Lionel, Maeder, André, Hirschi, Raphael, Yusof, Norhasliza, Groh, José, Farrell, Eoin, Murphy, Laura, and Choplin, Arthur

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

Context: Grids of stellar models, computed with the same physical ingredients, allow one to study the impact of a given physics on a broad range of initial conditions and are a key ingredient for modeling the evolution of galaxies. Aims: We present a grid of single star models for masses between 0.8 and 120 $M_\odot$, with and without rotation for a mass fraction of heavy element Z=0.006, representative of the Large Magellanic Cloud (LMC). Methods: We used the Geneva stellar evolution code. The evolution was computed until the end of the central carbon-burning phase, the early asymptotic giant branch phase, or the core helium-flash for massive, intermediate, and low mass stars, respectively. Results: The outputs of the present stellar models are well framed by the outputs of the two grids obtained by our group for metallicities above and below the one considered here. The models of the present work provide a good fit to the nitrogen surface enrichments observed during the main sequence for stars in the LMC with initial masses around 15 $M_\odot$. They also reproduce the slope of the luminosity function of red supergiants of the LMC well, which is a feature that is sensitive to the time-averaged mass loss rate over the red supergiant phase. The most massive black hole that can be formed from the present models at Z=0.006 is around 55 $M_\odot$. No model in the range of mass considered will enter into the pair-instability supernova regime, while the minimal mass to enter the region of pair pulsation instability is around 60 $M_\odot$ for the rotating models and 85 $M_\odot$ for the nonrotating ones. Conclusions: The present models are of particular interest for comparisons with observations in the LMC and also in the outer regions of the Milky Way. We provide public access to numerical tables that can be used for computing interpolated tracks and for population synthesis studies., Comment: 11 pages, 11 figures, published in A&A

Published
2022
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7. A pair of Sub-Neptunes transiting the bright K-dwarf TOI-1064 characterised with CHEOPS

Author

Wilson, Thomas G., Goffo, Elisa, Alibert, Yann, Gandolfi, Davide, Bonfanti, Andrea, Persson, Carina M., Cameron, Andrew Collier, Fridlund, Malcolm, Fossati, Luca, Korth, Judith, Benz, Willy, Deline, Adrien, Florén, Hans-Gustav, Guterman, Pascal, Adibekyan, Vardan, Hooton, Matthew J., Hoyer, Sergio, Leleu, Adrien, Mustill, Alexander James, Salmon, Sébastien, Sousa, Sérgio G., Suarez, Olga, Abe, Lyu, Agabi, Abdelkrim, Alonso, Roi, Anglada, Guillem, Asquier, Joel, Bárczy, Tamas, Navascues, David Barrado y, Barros, Susana C. C., Baumjohann, Wolfgang, Beck, Mathias, Beck, Thomas, Billot, Nicolas, Bonfils, Xavier, Brandeker, Alexis, Broeg, Christopher, Bryant, Edward M., Burleigh, Matthew R., Buttu, Marco, Cabrera, Juan, Charnoz, Sébastien, Ciardi, David R., Cloutier, Ryan, Cochran, William D., Collins, Karen A., Colón, Knicole D., Crouzet, Nicolas, Csizmadia, Szilard, Davies, Melvyn B., Deleuil, Magali, Delrez, Laetitia, Demangeon, Olivier, Demory, Brice-Olivier, Dragomir, Diana, Dransfield, Georgina, Ehrenreich, David, Erikson, Anders, Fortier, Andrea, Gan, Tianjun, Gill, Samuel, Gillon, Michaël, Gnilka, Crystal L., Grieves, Nolan, Grziwa, Sascha, Güdel, Manuel, Guillot, Tristan, Haldemann, Jonas, Heng, Kevin, Horne, Keith, Howell, Steve B., Isaak, Kate G., Jenkins, Jon M., Jensen, Eric L. N., Kiss, Laszlo, Lacedelli, Gaia, Lam, Kristine, Laskar, Jacques, Latham, David W., Etangs, Alain Lecavelier des, Lendl, Monika, Lester, Kathryn V., Levine, Alan M., Livingston, John, Lovis, Christophe, Luque, Rafael, Magrin, Demetrio, Marie-Sainte, Wenceslas, Maxted, Pierre F. L., Mayo, Andrew W., McLean, Brian, Mecina, Marko, Mékarnia, Djamel, Nascimbeni, Valerio, Nielsen, Louise D., Olofsson, Göran, Osborn, Hugh P., Osborne, Hannah L. M., Ottensamer, Roland, Pagano, Isabella, Pallé, Enric, Peter, Gisbert, Piotto, Giampaolo, Pollacco, Don, Queloz, Didier, Ragazzoni, Roberto, Rando, Nicola, Rauer, Heike, Redfield, Seth, Ribas, Ignasi, Ricker, George R., Rieder, Martin, Santos, Nuno C., Scandariato, Gaetano, Schmider, François-Xavier, Schwarz, Richard P., Scott, Nicholas J., Seager, Sara, Ségransan, Damien, Serrano, Luisa Maria, Simon, Attila E., Smith, Alexis M. S., Steller, Manfred, Stockdale, Chris, Szabó, Gyula, Thomas, Nicolas, Ting, Eric B., Triaud, Amaury H. M. J., Udry, Stéphane, Van Eylen, Vincent, Van Grootel, Valérie, Vanderspek, Roland K., Viotto, Valentina, Walton, Nicholas, and Winn, Joshua N.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

We report the discovery and characterisation of a pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 (TIC 79748331), initially detected in TESS photometry. To characterise the system, we performed and retrieved CHEOPS, TESS, and ground-based photometry, HARPS high-resolution spectroscopy, and Gemini speckle imaging. We characterise the host star and determine $T_{\rm eff, \star}=4734\pm67$ K, $R_{\star}=0.726\pm0.007$ $R_{\odot}$, and $M_{\star}=0.748\pm0.032$ $M_{\odot}$. We present a novel detrending method based on PSF shape-change modelling and demonstrate its suitability to correct flux variations in CHEOPS data. We confirm the planetary nature of both bodies and find that TOI-1064 b has an orbital period of $P_{\rm b}=6.44387\pm0.00003$ d, a radius of $R_{\rm b}=2.59\pm0.04$ $R_{\oplus}$, and a mass of $M_{\rm b}=13.5_{-1.8}^{+1.7}$ $M_{\oplus}$, whilst TOI-1064 c has an orbital period of $P_{\rm c}=12.22657^{+0.00005}_{-0.00004}$ d, a radius of $R_{\rm c}=2.65\pm0.04$ $R_{\oplus}$, and a 3$\sigma$ upper mass limit of 8.5 ${\rm M_{\oplus}}$. From the high-precision photometry we obtain radius uncertainties of $\sim$1.6%, allowing us to conduct internal structure and atmospheric escape modelling. TOI-1064 b is one of the densest, well-characterised sub-Neptunes, with a tenuous atmosphere that can be explained by the loss of a primordial envelope following migration through the protoplanetary disc. It is likely that TOI-1064 c has an extended atmosphere due to the tentative low density, however further RVs are needed to confirm this scenario and the similar radii, different masses nature of this system. The high-precision data and modelling of TOI-1064 b are important for planets in this region of mass-radius space, and it allows us to identify a trend in bulk density-stellar metallicity for massive sub-Neptunes that may hint at the formation of this population of planets., Comment: 30 pages, 24 figures, 6 tables including the Appendix; accepted for publication in MNRAS

Published
2022
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8. Asteroseismology of $\beta$ Cephei stars: The stellar inferences tested in hare and hound exercises

Author

Salmon, Sébastien, Eggenberger, Patrick, Montalbán, Josefina, Miglio, Andrea, Noels, Arlette, Buldgen, Gaël, Moyano, Facundo, and Meynet, Georges

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The $\beta$ Cephei pulsators are massive main-sequence stars, presenting low radial-order modes. These modes probe in particular the chemical gradient at the edge of the convective core. They hence give constraints on macroscopic processes, such as hydrodynamic or magnetic instabilities. Yet, it is not clear to what extent the seismic inferences depend on the physics employed for the stellar modelling or on the observational dataset. We investigate the observational constraints which are necessary to provide accurate constraints on the mixing processes in $\beta$ Cephei stars. We explore the importance of the identification of the angular degree of modes. Depending on the quality of the seismic dataset and the classical constraints, we estimate the precision achievable with asteroseismology. We propose a method extending the forward approach classically used to model $\beta$ Cephei stars The probability distributions of the asteroseismic-derived stellar parameters are obtained. With these distributions, we provide a systemic way to estimate the errors of the modelling. A particular effort is made to also include the theoretical uncertainties of the models. We then estimate the accuracy and precision of asteroseismology for $\beta$ Cephei stars in a series of hare and hound exercises. The exercises show that a set of four to five oscillation frequencies with an identified angular degree already leads to accurate inferences on the stellar parameters. Without the identification of the modes, the addition of other classical observational constraints allow to succeed the seismic modelling. When the micro-physics of the star and stellar models used for the modelling differ, the constraints derived on the internal structure remain valid if expressed in terms of acoustic variables. The characterisation of the mixing processes at the boundary of the convective core remain model-dependent., Comment: 17 pages, 14 figures, accepted for publication in A&A

Published
2021
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9. Transit detection of the long-period volatile-rich super-Earth $\nu^2$ Lupi d with $CHEOPS$

Author

Delrez, Laetitia, Ehrenreich, David, Alibert, Yann, Bonfanti, Andrea, Borsato, Luca, Fossati, Luca, Hooton, Matthew J., Hoyer, Sergio, Pozuelos, Francisco J., Salmon, Sébastien, Sulis, Sophia, Wilson, Thomas G., Adibekyan, Vardan, Bourrier, Vincent, Brandeker, Alexis, Charnoz, Sébastien, Deline, Adrien, Guterman, Pascal, Haldemann, Jonas, Hara, Nathan, Oshagh, Mahmoudreza, Sousa, Sergio G., Van Grootel, Valérie, Alonso, Roi, Escudé, Guillem Anglada, Bárczy, Tamás, Barrado, David, Barros, Susana C. C., Baumjohann, Wolfgang, Beck, Mathias, Bekkelien, Anja, Benz, Willy, Billot, Nicolas, Bonfils, Xavier, Broeg, Christopher, Cabrera, Juan, Cameron, Andrew Collier, Davies, Melvyn B., Deleuil, Magali, Delisle, Jean-Baptiste, Demangeon, Olivier D. S., Demory, Brice-Olivier, Erikson, Anders, Fortier, Andrea, Fridlund, Malcolm, Futyan, David, Gandolfi, Davide, Muñoz, Antonio Garcia, Gillon, Michaël, Guedel, Manuel, Heng, Kevin, Kiss, László, Laskar, Jacques, Etangs, Alain Lecavelier des, Lendl, Monika, Lovis, Christophe, Maxted, Pierre F. L., Nascimbeni, Valerio, Olofsson, Göran, Osborn, Hugh P., Pagano, Isabella, Pallé, Enric, Piotto, Giampaolo, Pollacco, Don, Queloz, Didier, Rauer, Heike, Ragazzoni, Roberto, Ribas, Ignasi, Santos, Nuno C., Scandariato, Gaetano, Ségransan, Damien, Simon, Attila E., Smith, Alexis M. S., Steller, Manfred, Szabó, Gyula M., Thomas, Nicolas, Udry, Stéphane, and Walton, Nicholas A.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Exoplanets transiting bright nearby stars are key objects for advancing our knowledge of planetary formation and evolution. The wealth of photons from the host star gives detailed access to the atmospheric, interior, and orbital properties of the planetary companions. $\nu^2$ Lupi (HD 136352) is a naked-eye ($V = 5.78$) Sun-like star that was discovered to host three low-mass planets with orbital periods of 11.6, 27.6, and 107.6 days via radial velocity monitoring (Udry et al. 2019). The two inner planets (b and c) were recently found to transit (Kane et al. 2020), prompting a photometric follow-up by the brand-new $CHaracterising\:ExOPlanets\:Satellite\:(CHEOPS)$. Here, we report that the outer planet d is also transiting, and measure its radius and mass to be $2.56\pm0.09$ $R_{\oplus}$ and $8.82\pm0.94$ $M_{\oplus}$, respectively. With its bright Sun-like star, long period, and mild irradiation ($\sim$5.7 times the irradiation of Earth), $\nu^2$ Lupi d unlocks a completely new region in the parameter space of exoplanets amenable to detailed characterization. We refine the properties of all three planets: planet b likely has a rocky mostly dry composition, while planets c and d seem to have retained small hydrogen-helium envelopes and a possibly large water fraction. This diversity of planetary compositions makes the $\nu^2$ Lupi system an excellent laboratory for testing formation and evolution models of low-mass planets., Comment: Published in Nature Astronomy. 60 pages, 18 Figures, 6 Tables. This is the authors' version of the manuscript. The final authenticated version is available online at https://www.nature.com/articles/s41550-021-01381-5

Published
2021
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10. Standard solar models: a perspective from updated solar neutrino fluxes and the gravity-mode period spacing

Author

Salmon, Sébastien, Buldgen, Gaël, Noels, Arlette, Eggenberger, Patrick, Scuflaire, Richard, and Meynet, Georges

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Context: The Sun is by far a privileged target for testing stellar models with unique precision. A recent concern appeared with the progress in the solar surface abundances derivation that has led to a decrease of the solar metallicity. While the ancient high-metallicity models were in fair agreement with other solar observational indicators, it is no longer the case for low-metallicity models. Recent collection of data are however promising to shed a new light on it. For instance, the Borexino collaboration released in 2020 the first-ever complete estimate of neutrinos emitted in the CNO cycle. It has reaffirmed the role of the neutrino constraints in the solar modelling process and its associated issues. In parallel, newly claimed detection of solar gravity modes of oscillations offers another opportunity of probing the stratification in the Sun's central layers. Aims: We propose to combine the diagnoses from neutrinos and helioseismology, both from pressure and gravity modes, for assessing the predictions of solar models. We compare in detail the different physical prescriptions currently at disposal for stellar model computations. Results: The CNO neutrino flux confirms a preference for high-metallicity models. Nevertheless, we found that mild modification of the nuclear screening factors can re-match low-metallicity model predictions to observed fluxes, although it does not restore the agreement with the helioseismic frequency ratios. Neither the high-metallicity or low-metallicity models are able to reproduce the gravity-mode period spacing. The disagreement is huge, more than 100$\sigma$ to the reported value. Reversely, the family of standard models narrows the expected range of the Sun's period spacing: between $\sim$2150 to $\sim$2190~s. Moreover, we show this indicator can constrain the chemical mixture, opacity, and to a lower extent nuclear reactions in solar models., Comment: 18 pages, 10 figures, accepted for publications in Astronomy and Astrophysics

Published
2021
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11. Reinvestigating $\alpha$ Cen AB in light of asteroseismic forward and inverse methods

Author

Salmon, Sébastien, Van Grootel, Valérie, Buldgen, Gaël, Dupret, Marc-Antoine, and Eggenberger, Patrick

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The $\alpha$ Cen stellar system is the closest neighbour to our Sun. Its main component is a binary composed of two main-sequence stars, one more massive than the Sun and one less massive. The system's bright magnitude led to a wealth of astronomical observations over a long period, making it an appealing testbed for stellar physics. In particular, detection of stellar pulsations in both $\alpha$ Cen A and B has revealed the potential of asteroseismology for determining its fundamental stellar parameters. Asteroseismic studies have also focused on the presence of a convective core in the A component, but as yet without definitive confirmation. Progress in the determination of solar surface abundances and stellar opacities have yielded new input for stellar theoretical models. We investigate their impact on a reference system such as $\alpha$ Cen AB. We seek to confirm the presence of a convective core in $\alpha$ Cen A by analysing the role of different stellar physics and the potential of asteroseismic inverse methods. We present a new series of asteroseismic calibrations carried out using forward approach modelling and including updated chemical mixture and opacities in the models. We then complement our analysis with help of recent asteroseismic diagnostic tools based on inverse methods developed for solar-like stars. The inclusion of an updated chemical mixture -- that is less metal-rich -- appears to reduce the predicted asteroseismic masses of each component. Neither classical asteroseismic indicators such as frequency ratios, nor asteroseismic inversions favour the presence of a convective core in $\alpha$ Cen A. The quality of the observational seismic dataset is the main limiting factor to settle the issue. Implementing new observing strategies to improve the precision on the pulsation frequencies would certainly refine the outcome of asteroseismology for this binary system., Comment: 16 pages, 8 figures, accepted for publication in Astronomy and Astrophysics

Published
2020
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12. Evolutionary models for ultracool dwarfs

Author

Fernandes, Catarina S., Van Grootel, Valerie, Salmon, Sebastien J. A. J., Aringer, Bernhard, Burgasser, Adam J., Scuflaire, Richard, Brassard, Pierre, and Fontaine, Gilles

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Ultracool dwarfs have emerged as key targets for searches of transiting exoplanets. Precise estimates of the host parameters (including mass, age, and radius) are fundamental to constrain the physical properties of orbiting exoplanets. We have extended our evolutionary code CLES (Code Li\'egeois d'Evolution Stellaire) to the ultracool dwarf regime. We include relevant equations of state for H, He, as well as C and O elements to cover the temperature-density regime of ultracool dwarf interiors. For various metallicities, we couple the interior models to two sets of model atmospheres as surface boundary conditions. We show that including C and O in the EOS has a significant effect close the H-burning limit mass. The typical systematic error associated with uncertainties in input physics in evolutionary models is $\sim 0.0005 M_\odot$. We test model results against observations for objects whose parameters have been determined from independent techniques. We are able to reproduce dynamical mass measurements of LSPM J1314+1320AB within $1\sigma$ with the condition of varying the metallicity (determined from calibrations) up to $2.5\sigma$. For GJ 65AB, a $2\sigma$ agreement is obtained between individual masses from differential astrometry and those from evolutionary models. We provide tables of ultracool dwarf models for various masses and metallicities that can be used as reference when estimating parameters for ultracool objects., Comment: 16 pages, 8 figures, 1 table, accepted for publication in ApJ

Published
2019
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13. What CoRoT tells us about {\delta} Scuti stars existence of a regular pattern and seismic indices to characterize stars

Author

Michel, Eric, Dupret, Marc-Antoine, Reese, Daniel, Ouazzani, Rhita-Maria, Debosscher, Jonas, Hernández, Antonio García, Belkacem, Kevin, Samadi, Reza, Salmon, Sébastien, Suarez, Juan Carlos, and Forteza, Sebastia Barceló

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Inspired by the so appealing example of red giants, where going from a handful of stars to thousands revealed the structure of the eigenspectrum, we inspected a large homogeneous set of around 1860 {\delta} Scuti stars observed with CoRoT. This unique data set reveals a common regular pattern which appears to be in agreement with island modes featured by theoretical non-perturbative treatments of fast rotation. The comparison of these data with models and linear stability calculations suggests that spectra can be fruitfully characterized to first order by a few parameters which might play the role of seismic indices for {\delta} Scuti stars, as {\Delta \nu} and {\nu_{max}} do for red giants. The existence of this pattern offers an observational support for guiding further theoretical works on fast rotation. It also provides a framework for further investigation of the observational material collected by CoRoT and Kepler. Finally, it sketches out the perspective of using {\delta} Scuti stars pulsations for ensemble asteroseismology., Comment: 7 pages, 9 figures, proc. of the Conference Seismology of the Sun and the Distant Stars 2016 Using Today s Successes to Prepare the Future, Joint TASC2 and KASC9 Workshop , SPACEINN and HELAS8 Conference, 11-15 July 2016, Angra do Hero\'ismo, Terceira-A\c{c}ores, Portugal

Published
2017
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14. First solar models with OPAS opacity tables

Author

Pennec, Maëlle Le, Turck-Chièze, Sylvaine, Salmon, Sébastien, Blancard, Christophe, Cossé, Philippe, Faussurier, Gérald, and Mondet, Guillaume

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However the particular case of Sun is still challenging. The helioseismic sound speed determination continues to disagree with the Standard Solar Model (SSM) prediction for about a decade, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this letter, we use the new OPAS opacity tables, recently available for solar modelling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes MESA and CLES that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models computed, for the most recent photospheric composition, with OPAS tables present improvements in the location of the base of the convective zone and in the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6 %. We finally carry out a comparison to a solar model computed with the OP opacity tables.

Published
2015
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15. BSG-Starcraft Radius Improvements of Particle Swarm Optimization Algorithm: An Application to Ceramic Matrix Composites

Author

Chamoret, Dominique, Salmon, Sébastien, Di Cesare, Noelie, Xu, Yingjie J., Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Siarry, Patrick, editor, Idoumghar, Lhassane, editor, and Lepagnot, Julien, editor

Published
2014
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16. Kepler observations of the variability in B-type stars

Author

Balona, Luis A., Pigulski, A., De Cat, P., Handler, Gerald, Gutiérrez-Soto, J., Engelbrecht, C.A., Frescura, F., Briquet, M., Cuypers, J., Daszyńska-Daszkiewicz, Jadwiga, Degroote, P., Dukes, R.J., Garcia, R.A., Green, E.M., Heber, U., Kawaler, Steve D., Lehmann, H., Leroy, B., Molenda-Zakowicz, Joanna, Neiner, Coralie, Østensen, Roy, Pricopi, D., Roxburgh, Ian, Salmon, Sebastien, Smith, M.A., Suárez, J.C., Suran, M., Szabó, R., Uytterhoeven, Katrien, Christensen-Dalsgaard, Jørgen, Kjeldsen, Hans, Caldwell, D.A., Girouard, F.R., and Sanderfer, D.T.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

The analysis of the light curves of 48 B-type stars observed by Kepler is presented. Among these are 15 pulsating stars, all of which show low frequencies, characteristic of slowly pulsating B (SPB) stars. Seven of these stars also show a few weak, isolated high frequencies and they could be considered as SPB/β Cephei (β Cep) hybrids. In all cases, the frequency spectra are quite different from what is seen from ground-based observations. We suggest that this is because most of the low frequencies are modes of high degree which are predicted to be unstable in models of mid-B stars. We find that there are non-pulsating stars within the β Cep and SPB instability strips. Apart from the pulsating stars, we can identify stars with frequency groupings similar to what is seen in Be stars but which are not Be stars. The origin of the groupings is not clear, but may be related to rotation. We find periodic variations in other stars which we attribute to proximity effects in binary systems or possibly rotational modulation. We find no evidence for pulsating stars between the cool edge of the SPB and the hot edge of the δ Sct instability strips. None of the stars shows the broad features which can be attributed to stochastically excited modes as recently proposed. Among our sample of B stars are two chemically peculiar stars, one of which is a HgMn star showing rotational modulation in the light curve.

Published
2011

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