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1. Hints of auroral and magnetospheric polarized radio emission from the scallop-shell star 2MASS J05082729$-$2101444

Author

Kaur, Simranpreet, Viganò, Daniele, Béjar, Víctor J. S., Monge, Álvaro Sánchez, Morata, Òscar, Kansabanik, Devojyoti, Girart, Josep Miquel, Morales, Juan Carlos, Anglada-Escudé, Guillem, Murgas, Felipe, Shan, Yutong, Ilin, Ekaterina, Pérez-Torres, Miguel, Osorio, María Rosa Zapatero, Amado, Pedro J., Caballero, José A., Del Sordo, Fabio, Palle, Enric, Quirrenbach, Andreas, Reiners, Ansgar, and Ribas, Ignasi

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Scallop-shell stars, a recently discovered class of young M dwarfs, show complex optical light curves that are characterized by periodic dips as well as other features that are stable over tens to hundreds of rotation cycles. The origin of these features is not well-understood. 2MASS J05082729$-$2101444 is a $\sim$25 Myr old scallop-shell star that was identified using TESS data; it has a photometric period of 6.73h that has been attributed to rotation. Of the $\sim$50 recently confirmed scallop-shell stars, it is one of the few detected at radio frequencies between 1 and 8 GHz. We observed this rare system with the upgraded Giant Meterwave Radio Telescope at 575--720 MHz, covering 88% of the photometric period in each of the two observations scheduled almost a month apart in 2023. We detected $\sim$millijansky emission from the target in both epochs, with a significant circular polarization fraction: $|V/I|\sim$20--50%. The 3.5-min phase-folded light curves reveal unique variability in circular polarization, showing an $\sim$hour-long helicity reversal in both epochs, similar in amplitude, length, and (possibly) phase. These results suggest two emission components: The first is a persistent, moderately polarized component possibly ascribable to gyro-synchrotron emission driven by centrifugal breakout events. The second is a highly polarized, short burst-like component, likely due to an electron cyclotron maser (ECM), indicative of auroral emission and potentially responsible for the helicity reversal. To explain this, we discuss the different origins of the plasma responsible for the radio emission, including the possibility that the occulting material is acting as a plasma source. Future coordinated multifrequency radio and optical observations can further constrain the underlying scenario, as well as the magnetic geometry of the system, if we assume an ECM-like auroral emission., Comment: 9 pages, 5 figures, 1 table, Accepted for publication in Astronomy & Astrophysics Letters

Published
2024
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2. 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, César, 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, a, Lorena Acu, 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, Balagueró, Pau Ballber, Balestra, Andrea, Ball, Warrick, Ballans, Herve, Ballot, Jerome, Barban, Caroline, Barbary, Gaële, Barbieri, Mauro, Forteza, Sebasti 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 J. A., 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, Gomez, Juan-Francisco Cabrero, Calderone, Flavia, Cameron, Robert, Cameron, Andrew, Campante, Tiago, Gestal, Néstor Campos, 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, Jørgen, Church, Ross, Claret, Antonio, Clarke, Cathie, Claudi, Riccardo, Clermont, Lionel, Coelho, Hugo, Coelho, Joao, Cogato, Fabrizio, Colomé, Josep, Condamin, Mathieu, García, Fernando Conde, 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, Gómez, Álvaro de Pedraza, de Plaa, Jelle, De Ridder, Joris, Deal, Morgan, Decin, Leen, Deeg, Hans, Innocenti, Scilla Degl, Deheuvels, Sebastien, del Burgo, Carlos, Del Sordo, Fabio, Delgado-Mena, Elisa, Demangeon, Olivier, Denk, Tilmann, Derekas, Aliz, Desert, Jean-Michel, 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, ez, Lucía Espinosa Yá, Estrela, In s, Evans, Dafydd Wyn, Fabbian, Damian, Fabrizio, Michele, Faria, João Pedro, Farina, Maria, Farinato, Jacopo, Feliz, Dax, Feltzing, Sofia, Fenouillet, Thomas, Fernández, Miguel, 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, Sempere, Paloma I. Gallego, Galli, Emanuele, García, 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, Melchor, Alejandro Gonzalo, Gorius, Nicolas, Gouel, Pierre-Vincent, Goulty, Duncan, Granata, Valentina, Grenfell, John Lee, bach, Denis Grie, Grolleau, Emmanuel, Grouffal, Salomé, Grziwa, Sascha, Guarcello, Mario Giuseppe, Gueguen, Lo c, Guenther, Eike Wolf, Guilhem, Terrasa, Guillerot, Lucas, Guillot, Tristan, 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, Herbst, Konstantin, 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, Kucinskas, 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, Lee, Katherine, 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, Manjón, Andres, Mann, Andrew, Mantovan, Giacomo, Marafatto, Luca, Marconi, Marcella, Mardling, Rosemary, Marigo, Paola, Marinoni, Silvia, Marques, rico, Marques, Joao Pedro, Marrese, Paola Maria, Marshall, Douglas, Perales, Silvia Martínez, Mary, David, Marzari, Francesco, Masana, Eduard, Mascher, Andrina, Mathis, Stéphane, Mathur, Savita, Vodopivec, Iris Martín, 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., Sánchez, Francisco Montoro, Morales, Juan Carlos, Morales-Calderon, Maria, Morbidelli, Alessandro, Mordasini, Christoph, Moreau, Chrystel, Morel, Thierry, Morello, Guiseppe, Morin, Julien, Mortier, Annelies, Mosser, Beno t, 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, Stefania, 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, Quirrenbach, Andreas, Reina, 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, Ortiz, José Ramón Rodón, Rodríguez, María Teresa Rodrigo, Amor, Alberto Rodríguez, 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, Pé, Amaia Santiago, Santoli, Francesco, Santos, ngela 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, vanda, 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, Weingrill, 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

3. Probable Dormant Neutron Star in a Short-Period Binary System

Author

Mazeh, Tsevi, Faigler, Simchon, Bashi, Dolev, Shahaf, Sahar, Davidson, Niv, Green, Matthew, Gomel, Roy, Maoz, Dan, Sussholz, Amitay, Dong, Subo, Zhang, Haotong, Liu, Jifeng, Wang, Song, Luo, Ali, Zheng, Zheng, Hallakoun, Na'ama, Perdelwitz, Volker, Latham, David W., Ribas, Ignasi, Baroch, David, Morales, Juan Carlos, Nagel, Evangelos, Santos, Nuno C., Ciardi, David R., Christiansen, Jessie L., Lund, Michael B., and Winn, Joshua N.

Subjects
Astrophysics - Solar and Stellar Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We have identified 2XMM J125556.57+565846.4, at a distance of 600 pc, as a binary system consisting of a normal star and a probable dormant neutron star. Optical spectra exhibit a slightly evolved F-type single star, displaying periodic Doppler shifts with a 2.76-day Keplerian circular orbit, with no indication of light from a secondary component. Optical and UV photometry reveal ellipsoidal variations with half the orbital period, due to the tidal deformation of the F star. The mass of the unseen companion is constrained to the range $1.1$--$2.1\,M_{\odot}$ at $3\sigma$ confidence, with the median of the mass distribution at $1.4\,M_{\odot}$, the typical mass of known neutron stars. A main-sequence star cannot masquerade as the dark companion. The distribution of possible companion masses still allows for the possibility of a very massive white dwarf. The companion itself could also be a close pair consisting of a white dwarf and an M star, or two white dwarfs, although the binary evolution that would lead to such a close triple system is unlikely. Similar ambiguities regarding the certain identification of a dormant neutron star are bound to affect most future discoveries of this type of non-interacting system. If the system indeed contains a dormant neutron star, it will become, in the future, a bright X-ray source and afterwards might even host a millisecond pulsar., Comment: 35 pages, 21 figures. accepted for publication in MNRAS

Published
2022
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5. A transiting, temperate mini-Neptune orbiting the M dwarf TOI-1759 unveiled by TESS

Author

Espinoza, Néstor, Pallé, Enric, Kemmer, Jonas, Luque, Rafael, Caballero, José A., Cifuentes, Carlos, Herrero, Enrique, Béjar, Víctor J. Sánchez, Stock, Stephan, Molaverdikhani, Karan, Morello, Giuseppe, Kossakowski, Diana, Schlecker, Martin, Amado, Pedro J., Bluhm, Paz, Cortés-Contreras, Miriam, Henning, Thomas, Kreidberg, Laura, Kürster, Martin, Lafarga, Marina, Lodieu, Nicolas, Morales, Juan Carlos, Oshagh, Mahmoudreza, Passegger, Vera M., Pavlov, Alexey, Quirrenbach, Andreas, Reffert, Sabine, Reiners, Ansgar, Ribas, Ignasi, Rodríguez, Eloy, López, Cristina Rodríguez, Schweitzer, Andreas, Trifonov, Trifon, Chaturvedi, Priyanka, Dreizler, Stefan, Jeffers, Sandra V., Kaminski, Adrian, López-González, María José, Lillo-Box, Jorge, Montes, David, Nowak, Grzegorz, Pedraz, Santos, Vanaverbeke, Siegfried, Osorio, Maria R. Zapatero, Zechmeister, Mathias, Collins, Karen A., Girardin, Eric, Guerra, Pere, Naves, Ramon, Crossfield, Ian J. M., Matthews, Elisabeth C., Howell, Steve B., Ciardi, David R., Gonzales, Erica, Matson, Rachel A., Beichman, Charles A., Schlieder, Joshua E., Barclay, Thomas, Vezie, Michael, Villaseñor, Jesus Noel, Daylan, Tansu, Mireies, Ismael, Dragomir, Diana, Twicken, Joseph D., Jenkins, Jon, Winn, Joshua N., Latham, David, Ricker, George, and Seager, Sara

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery and characterization of TOI-1759~b, a temperate (400 K) sub-Neptune-sized exoplanet orbiting the M~dwarf TOI-1759 (TIC 408636441). TOI-1759 b was observed by TESS to transit on sectors 16, 17 and 24, with only one transit observed per sector, creating an ambiguity on the orbital period of the planet candidate. Ground-based photometric observations, combined with radial-velocity measurements obtained with the CARMENES spectrograph, confirm an actual period of $18.85019 \pm 0.00014$ d. A joint analysis of all available photometry and radial velocities reveal a radius of $3.17 \pm 0.10\,R_\oplus$ and a mass of $10.8 \pm 1.5\,M_\oplus$. Combining this with the stellar properties derived for TOI-1759 ($R_\star = 0.597 \pm 0.015\,R_\odot$; $M_\star = 0.606 \pm 0.020\,M_\odot$; $T_{\textrm{eff}} = 4065 \pm 51$ K), we compute a transmission spectroscopic metric (TSM) value of over 80 for the planet, making it a good target for transmission spectroscopy studies. TOI-1759 b is among the top five temperate, small exoplanets ($T_\textrm{eq} < 500$ K, $R_p < 4 \,R_\oplus$) with the highest TSM discovered to date. Two additional signals with periods of 80 d and $>$ 200 d seem to be present in our radial velocities. While our data suggest both could arise from stellar activity, the later signal's source and periodicity are hard to pinpoint given the $\sim 200$ d baseline of our radial-velocity campaign with CARMENES. Longer baseline radial-velocity campaigns should be performed in order to unveil the true nature of this long period signal., Comment: 22 pages, 10 figures, 7 tables. AJ in press

Published
2022
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8. The CARMENES search for exoplanets around M dwarfs. Stellar atmospheric parameters of target stars with SteParSyn

Author

Marfil, Emilio, Tabernero, Hugo M., Montes, David, Caballero, Jose A., Lazaro, Francisco J., Hernandez, Jonay I. Gonzalez, Nagel, Evangelos, Passegger, Vera M., Schweitzer, Andreas, Ribas, Ignasi, Reiners, Ansgar, Quirrenbach, Andreas, Amado, Pedro J., Cifuentes, Carlos, Cortes-Contreras, Miriam, Dreizler, Stefan, Duque-Arribas, Christian, Galadi-Enriquez, David, Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kurster, Martin, Lafarga, Marina, Lopez-Gallifa, Alvaro, Morales, Juan Carlos, Shan, Yutong, and Zechmeister, Mathias

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

We determined effective temperatures, surface gravities, and metallicities for a sample of 343 M dwarfs observed with CARMENES, the double-channel, high-resolution spectrograph installed at the 3.5 m telescope at Calar Alto Observatory. We employed SteParSyn, a Bayesian spectral synthesis implementation particularly designed to infer the stellar atmospheric parameters of late-type stars following a Markov chain Monte Carlo approach. We made use of the BT-Settl model atmospheres and the radiative transfer code turbospectrum to compute a grid of synthetic spectra around 75 magnetically insensitive Fe I and Ti I lines plus the TiO $\gamma$ and $\epsilon$ bands. To avoid any potential degeneracy in the parameter space, we imposed Bayesian priors on Teff and log g based on the comprehensive, multi-band photometric data available for the sample. We find that this methodology is suitable down to M7.0 V, where refractory metals such as Ti are expected to condense in the stellar photospheres. The derived $T_{\rm eff}$, $\log{g}$, and [Fe/H] range from 3000 to 4200 K, 4.5 to 5.3 dex, and -0.7 to 0.2 dex, respectively. Although our $T_{\rm eff}$ scale is in good agreement with the literature, we report large discrepancies in the [Fe/H] scales, which might arise from the different methodologies and sets of lines considered. However, our [Fe/H] is in agreement with the metallicity distribution of FGK-type stars in the solar neighbourhood and correlates well with the kinematic membership of the targets in the Galactic populations. Lastly, excellent agreement in $T_{\rm eff}$ is found for M dwarfs with interferometric angular diameter measurements, as well as in the [Fe/H] between the components in the wide physical FGK+M and M+M systems included in our sample., Comment: 42 pages, 32 figures. Accepted for publication in A&A

Published
2021
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11. The CARMENES search for exoplanets around M dwarfs: Not-so-fine hyperfine-split vanadium lines in cool star spectra

Author

Shan, Yutong, Reiners, Ansgar, Fabbian, Damian, Marfil, Emilio, Montes, David, Tabernero, Hugo M., Ribas, Ignasi, Caballero, Jose A., Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Jesus, Bejar, Victor J. S., Cortes-Contreras, Miriam, Dreizler, Stefan, Hatzes, Artie P., Henning, Thomas, Jeffers, Sandra V., Kaminski, Adrian, Kurster, Martin, Lafarga, Marina, Morales, Juan Carlos, Nagel, Evangelos, Palle, Enric, Passegger, Vera M., Lopez, Cristina Rodriguez, Schweitzer, Andreas, and Zechmeister, Mathias

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

(Abridged) We characterize a series of neutral vanadium atomic absorption lines in the 800--910nm wavelength region of high signal-to-noise, high-resolution, telluric-corrected M-dwarf spectra from the CARMENES survey. Many of these lines are prominent and exhibit a distinctive broad and flat-bottom shape, which is a result of hyperfine structure (HFS). We investigate the potential and implications of these HFS split lines for abundance analysis of cool stars. With standard spectral synthesis routines, as provided by the spectroscopy software iSpec and the latest atomic data (including HFS) available from the VALD3 database, we modeled these striking line profiles. We used them to measure V abundances of cool dwarfs. We determined V abundances for 135 early M dwarfs (M0.0V to M3.5V) in the CARMENES guaranteed time observations sample. They exhibit a [V/Fe]-[Fe/H] trend consistent with that derived from nearby FG dwarfs. The tight ($\pm$ 0.1 dex) correlation between [V/H] and [Fe/H] suggests the potential application of V as an alternative metallicity indicator in M dwarfs. We also show hints that neglecting to model HFS could partially explain the temperature correlation in V abundance measurements observed in previous studies of samples involving dwarf stars with $T_{\rm eff} \lesssim 5300$K. Our work suggests that HFS can impact certain absorption lines in cool photospheres more severely than in Sun-like ones. Therefore, we advocate that HFS should be carefully treated in abundance studies in stars cooler than $\sim 5000$K. On the other hand, strong HFS split lines in high-resolution spectra present an opportunity for precision chemical analyses of large samples of cool stars. The V-to-Fe trends exhibited by the local M dwarfs continue to challenge theoretical models of V production in the Galaxy., Comment: 26 pages, 17 figures, accepted for publication in A&A

Published
2021
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12. Ariel: Enabling planetary science across light-years

Author

Tinetti, Giovanna, Eccleston, Paul, Haswell, Carole, Lagage, Pierre-Olivier, Leconte, Jérémy, Lüftinger, Theresa, Micela, Giusi, Min, Michel, Pilbratt, Göran, Puig, Ludovic, Swain, Mark, Testi, Leonardo, Turrini, Diego, Vandenbussche, Bart, Osorio, Maria Rosa Zapatero, Aret, Anna, Beaulieu, Jean-Philippe, Buchhave, Lars, Ferus, Martin, Griffin, Matt, Guedel, Manuel, Hartogh, Paul, Machado, Pedro, Malaguti, Giuseppe, Pallé, Enric, Rataj, Mirek, Ray, Tom, Ribas, Ignasi, Szabó, Robert, Tan, Jonathan, Werner, Stephanie, Ratti, Francesco, Scharmberg, Carsten, Salvignol, Jean-Christophe, Boudin, Nathalie, Halain, Jean-Philippe, Haag, Martin, Crouzet, Pierre-Elie, Kohley, Ralf, Symonds, Kate, Renk, Florian, Caldwell, Andrew, Abreu, Manuel, Alonso, Gustavo, Amiaux, Jerome, Berthé, Michel, Bishop, Georgia, Bowles, Neil, Carmona, Manuel, Coffey, Deirdre, Colomé, Josep, Crook, Martin, Désjonqueres, Lucile, Díaz, José J., Drummond, Rachel, Focardi, Mauro, Gómez, Jose M., Holmes, Warren, Krijger, Matthijs, Kovacs, Zsolt, Hunt, Tom, Machado, Richardo, Morgante, Gianluca, Ollivier, Marc, Ottensamer, Roland, Pace, Emanuele, Pagano, Teresa, Pascale, Enzo, Pearson, Chris, Pedersen, Søren Møller, Pniel, Moshe, Roose, Stéphane, Savini, Giorgio, Stamper, Richard, Szirovicza, Peter, Szoke, Janos, Tosh, Ian, Vilardell, Francesc, Barstow, Joanna, Borsato, Luca, Casewell, Sarah, Changeat, Quentin, Charnay, Benjamin, Civiš, Svatopluk, Foresto, Vincent Coudé du, Coustenis, Athena, Cowan, Nicolas, Danielski, Camilla, Demangeon, Olivier, Drossart, Pierre, Edwards, Billy N., Gilli, Gabriella, Encrenaz, Therese, Kiss, Csaba, Kokori, Anastasia, Ikoma, Masahiro, Morales, Juan Carlos, Mendonça, João, Moneti, Andrea, Mugnai, Lorenzo, Muñoz, Antonio García, Helled, Ravit, Kama, Mihkel, Miguel, Yamila, Nikolaou, Nikos, Pagano, Isabella, Panic, Olja, Rengel, Miriam, Rickman, Hans, Rocchetto, Marco, Sarkar, Subhajit, Selsis, Franck, Tennyson, Jonathan, Tsiaras, Angelos, Venot, Olivia, Vida, Krisztián, Waldmann, Ingo P., Yurchenko, Sergey, Szabó, Gyula, Zellem, Rob, Al-Refaie, Ahmed, Alvarez, Javier Perez, Anisman, Lara, Arhancet, Axel, Ateca, Jaume, Baeyens, Robin, Barnes, John R., Bell, Taylor, Benatti, Serena, Biazzo, Katia, Błęcka, Maria, Bonomo, Aldo Stefano, Bosch, José, Bossini, Diego, Bourgalais, Jeremy, Brienza, Daniele, Brucalassi, Anna, Bruno, Giovanni, Caines, Hamish, Calcutt, Simon, Campante, Tiago, Canestrari, Rodolfo, Cann, Nick, Casali, Giada, Casas, Albert, Cassone, Giuseppe, Cara, Christophe, Carone, Ludmila, Carrasco, Nathalie, Chioetto, Paolo, Cortecchia, Fausto, Czupalla, Markus, Chubb, Katy L., Ciaravella, Angela, Claret, Antonio, Claudi, Riccardo, Codella, Claudio, Comas, Maya Garcia, Cracchiolo, Gianluca, Cubillos, Patricio, Da Peppo, Vania, Decin, Leen, Dejabrun, Clemence, Delgado-Mena, Elisa, Di Giorgio, Anna, Diolaiti, Emiliano, Dorn, Caroline, Doublier, Vanessa, Doumayrou, Eric, Dransfield, Georgina, Dumaye, Luc, Dunford, Emma, Escobar, Antonio Jimenez, Van Eylen, Vincent, Farina, Maria, Fedele, Davide, Fernández, Alejandro, Fleury, Benjamin, Fonte, Sergio, Fontignie, Jean, Fossati, Luca, Funke, Bernd, Galy, Camille, Garai, Zoltán, García, Andrés, García-Rigo, Alberto, Garufi, Antonio, Sacco, Giuseppe Germano, Giacobbe, Paolo, Gómez, Alejandro, Gonzalez, Arturo, Gonzalez-Galindo, Francisco, Grassi, Davide, Griffith, Caitlin, Guarcello, Mario Giuseppe, Goujon, Audrey, Gressier, Amélie, Grzegorczyk, Aleksandra, Guillot, Tristan, Guilluy, Gloria, Hargrave, Peter, Hellin, Marie-Laure, Herrero, Enrique, Hills, Matt, Horeau, Benoit, Ito, Yuichi, Jessen, Niels Christian, Kabath, Petr, Kálmán, Szilárd, Kawashima, Yui, Kimura, Tadahiro, Knížek, Antonín, Kreidberg, Laura, Kruid, Ronald, Kruijssen, Diederik J. M., Kubelík, Petr, Lara, Luisa, Lebonnois, Sebastien, Lee, David, Lefevre, Maxence, Lichtenberg, Tim, Locci, Daniele, Lombini, Matteo, Lopez, Alejandro Sanchez, Lorenzani, Andrea, MacDonald, Ryan, Magrini, Laura, Maldonado, Jesus, Marcq, Emmanuel, Migliorini, Alessandra, Modirrousta-Galian, Darius, Molaverdikhani, Karan, Molinari, Sergio, Mollière, Paul, Moreau, Vincent, Morello, Giuseppe, Morinaud, Gilles, Morvan, Mario, Moses, Julianne I., Mouzali, Salima, Nakhjiri, Nariman, Naponiello, Luca, Narita, Norio, Nascimbeni, Valerio, Nikolaou, Athanasia, Noce, Vladimiro, Oliva, Fabrizio, Palladino, Pietro, Papageorgiou, Andreas, Parmentier, Vivien, Peres, Giovanni, Pérez, Javier, Perez-Hoyos, Santiago, Perger, Manuel, Pestellini, Cesare Cecchi, Petralia, Antonino, Philippon, Anne, Piccialli, Arianna, Pignatari, Marco, Piotto, Giampaolo, Podio, Linda, Polenta, Gianluca, Preti, Giampaolo, Pribulla, Theodor, Puertas, Manuel Lopez, Rainer, Monica, Reess, Jean-Michel, Rimmer, Paul, Robert, Séverine, Rosich, Albert, Rossi, Loic, Rust, Duncan, Saleh, Ayman, Sanna, Nicoletta, Schisano, Eugenio, Schreiber, Laura, Schwartz, Victor, Scippa, Antonio, Seli, Bálint, Shibata, Sho, Simpson, Caroline, Shorttle, Oliver, Skaf, N., Skup, Konrad, Sobiecki, Mateusz, Sousa, Sergio, Sozzetti, Alessandro, Šponer, Judit, Steiger, Lukas, Tanga, Paolo, Tackley, Paul, Taylor, Jake, Tecza, Matthias, Terenzi, Luca, Tremblin, Pascal, Tozzi, Andrea, Triaud, Amaury, Trompet, Loïc, Tsai, Shang-Min, Tsantaki, Maria, Valencia, Diana, Vandaele, Ann Carine, Van der Swaelmen, Mathieu, Vardan, Adibekyan, Vasisht, Gautam, Vazan, Allona, Del Vecchio, Ciro, Waltham, Dave, Wawer, Piotr, Widemann, Thomas, Wolkenberg, Paulina, Yip, Gordon Hou, Yung, Yuk, Zilinskas, Mantas, Zingales, Tiziano, and Zuppella, Paola

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

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution., Comment: Ariel Definition Study Report, 147 pages. Reviewed by ESA Science Advisory Structure in November 2020. Original document available at: https://www.cosmos.esa.int/documents/1783156/3267291/Ariel_RedBook_Nov2020.pdf/

Published
2021

13. Ancillary science with Ariel: Feasibility and scientific potential of young stellar object observations

Author

Gyűrűs, Boldizsár I., Kiss, Csaba, Morales, Juan Carlos, Nakhjiri, Navid, Marton, Gábor, Ábrahám, Péter, Kóspál, Ágnes, Moór, Attila, Szabó, Gyula M., and Szabó, Róbert

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

To investigate the feasibility of ancillary target observations with ESA's Ariel mission, we compiled a list of potentially interesting young stars: FUors, systems harbouring extreme debris discs and a larger sample of young stellar objects showing strong near/mid-infrared excess. These objects can be observed as additional targets in the waiting times between the scheduled exoplanet transit and occultation observations. After analyzing the schedule for Ariel an algorithm was constructed to find the optimal target to be observed in each gap. The selection was mainly based on the slew and stabilization time needed to observe the selected YSO, but it also incorporated the scientific importance of the targets and whether they have already been sufficiently measured. After acquiring an adequately large sample of simulation data, it was concluded that approximately 99.2% of the available -- at least one hour long -- gaps could be used effectively. With an average slewing and stabilization time of about 16.7 minutes between scheduled exoplanet transits and ancillary targets, this corresponds to an additional $2881 \pm 56$ hours of active data gathering. When this additional time is used to observe our selected 200 ancillary targets, a typical signal-to-noise ratio of $\sim$10$^4$ can be achieved along the whole spectral window covered by Ariel., Comment: Accepted for publication in Experimental Astronomy

Published
2021
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14. Auto-correlation functions of astrophysical processes, and their relation to Gaussian processes; Application to radial velocities of different starspot configurations

Author

Perger, Manuel, Anglada-Escudé, Guillem, Ribas, Ignasi, Rosich, Albert, Herrero, Enrique, and Morales, Juan Carlos

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

Accounting for the effects of stellar magnetic phenomena is indispensable to fully exploit radial velocities (RVs). Correlated time variations are often mitigated by Gaussian processes (GP). They rely on fitting kernel functions that are motivated on mathematical grounds, and whose physical interpretation is often elusive. We aim to establish a connection between stellar activity affecting RVs and their correlations with physical parameters, and compare this connection with kernels used in the literature. We use simple activity models to investigate the relationship between the physical processes generating the signals and the covariances typically found in data, and to demonstrate the qualitative behaviour of this relationship. We use the StarSim code to calculate RVs of an M dwarf with different realistic evolving spot configurations. Their auto-correlation functions (ACF) show a very specific behaviour and are related to the kernel. GP regression is performed using a quasi-periodic (QP) and harmonic oscillator kernels. Comparison of the resulting kernels with the exact ACFs allows us to cross-match the kernel hyper-parameters with the introduced physical values, study the overall capabilities of the kernels, and improve their definition. We find that the QP kernel provides a more straightforward interpretation of the physics. It is able to consistently recover both the introduced rotation period P and the spot lifetime. Our study indicates that the performance can be enhanced by fixing the form factor w and adding a physically motivated cosine term with period P/2, where the contribution to the ACF for the different spot configurations differs significantly. The new quasi-periodic with cosine kernel leads to significantly better model likelihoods, can potentially distinguish between different spot configurations, and can thereby improve the sensitivity of RV exoplanet searches.

Published
2020
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15. Weighing stars from birth to death: mass determination methods across the HRD

Author

Serenelli, Aldo, Weiss, Achim, Aerts, Conny, Angelou, George C., Baroch, David, Bastian, Nate, Beck, Paul G., Bergemann, Maria, Bestenlehner, Joachim M., Czekala, Ian, Elias-Rosa, Nancy, Escorza, Ana, Van Eylen, Vincent, Feuillet, Diane K., Gandolfi, Davide, Gieles, Mark, Girardi, Leo, Lebreton, Yveline, Lodieu, Nicolas, Martig, Marie, Bertolami, Marcelo M. Miller, Mombarg, Joey S. G., Morales, Juan Carlos, Moya, Andres, Nsamba, Benard, Pavlovski, Kresimir, Pedersen, May G., Ribas, Ignasi, Schneider, Fabian R. N., Aguirre, Victor Silva, Stassun, Keivan G., Tolstoy, Eline, Tremblay, Pier-Emmanuel, and Zwintz, Konstanze

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

The mass of a star is the most fundamental parameter for its structure, evolution, and final fate. It is particularly important for any kind of stellar archaeology and characterization of exoplanets. There exists a variety of methods in astronomy to estimate or determine it. In this review we present a significant number of such methods, beginning with the most direct and model-independent approach using detached eclipsing binaries. We then move to more indirect and model-dependent methods, such as the quite commonly used isochrone or stellar track fitting. The arrival of quantitative asteroseismology has opened a completely new approach to determine stellar masses and to complement and improve the accuracy of other methods. We include methods for different evolutionary stages, from the pre-main sequence to evolved (super)giants and final remnants. For all methods uncertainties and restrictions will be discussed. We provide lists of altogether more than 200 benchmark stars with relative mass accuracies between $[0.3,2]\%$ for the covered mass range of $M\in [0.1,16]\,\msun$, $75\%$ of which are stars burning hydrogen in their core and the other $25\%$ covering all other evolved stages. We close with a recommendation how to combine various methods to arrive at a "mass-ladder" for stars., Comment: Invited review article for The Astronomy and Astrophysics Review. 146 pages, 16 figures, 11 tables. Accepted version by the Journal. It includes summary figure of accuracy/precision of methods for mass ranges and summary table for individual methods

Published
2020
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19. COVID-19 Severity Classification Using a Hierarchical Classification Deep Learning Model

Author

Ortiz, Sergio, Morales, Juan Carlos, Rojas, Fernando, Valenzuela, Olga, Herrera, Luis Javier, Rojas, Ignacio, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Rojas, Ignacio, editor, Valenzuela, Olga, editor, Rojas, Fernando, editor, Herrera, Luis Javier, editor, and Ortuño, Francisco, editor

Published
2022
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22. The Ariel ground segment and instrument operations science data centre: Organization, operation, calibration, products and pipeline

Author

Pearson, Chris, Malaguti, Giuseppe, Sarkar, Subhajit, Papageorgiou, Andreas, Krijger, Matthijs, Pascale, Enzo, Beaulieu, Jean-Philippe, Colomé, Josep, Diolaiti, Emiliano, Doublier, Vanessa, Eccleston, Paul, Micela, Giusi, Moneti, Andrea, Morales, Juan Carlos, Nakhjiri, Nariman, Polenta, Gianluca, Ribas, Ignasi, Tinetti, Giovanna, Kohley, Ralf, Pilbratt, Göran, Birkmann, Stephan, de Oliveira, Catarina Alves, Rank-Lüftinger, Theresa, Puig, Ludovic, Salvignol, Jean-Christophe, and Symonds, Kate

Published
2022
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24. Comparison of Fusion Methodologies Using CNV and RNA-Seq for Cancer Classification: A Case Study on Non-Small-Cell Lung Cancer

Author

Carrillo-Perez, Francisco, Morales, Juan Carlos, Castillo-Secilla, Daniel, Guillen, Alberto, Rojas, Ignacio, Herrera, Luis Javier, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Woeginger, Gerhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Rojas, Ignacio, editor, Castillo-Secilla, Daniel, editor, Herrera, Luis Javier, editor, and Pomares, Héctor, editor

Published
2021
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28. DNA G‑Quadruplexes in the genome of Trypanosoma cruzi as potential therapeutic targets for Chagas disease: dithienylethene ligands as effective antiparasitic agents

Author

Pérez-Soto, Manuel, primary, Ramos-Soriano, Javier, additional, Peñalver, Pablo, additional, Belmonte-Reche, Efres, additional, O'Hagan, Michael, additional, Cucchiarini, Anne, additional, Mergny, Jean-Louis, additional, Galán, Carmen, additional, López-López, Manuel Carlos, additional, Thomas, Carmen, additional, and Morales, Juan Carlos, additional

Published
2024
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33. Cortistatin as a Novel Multimodal Therapy for the Treatment of Parkinson’s Disease

Author

Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Serrano-Martínez, Ignacio, Pedreño, M., Castillo-González, Julia, Ferraz-de-Paula, Viviane, Vargas Rodríguez, Pablo, Forte-Lago, Irene, Caro, Marta, Campos-Salinas, Jenny, Villadiego, Javier, Peñalver, Pablo, Morales, Juan Carlos, Delgado, Mario, González-Rey, Elena, Junta de Andalucía, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Serrano-Martínez, Ignacio, Pedreño, M., Castillo-González, Julia, Ferraz-de-Paula, Viviane, Vargas Rodríguez, Pablo, Forte-Lago, Irene, Caro, Marta, Campos-Salinas, Jenny, Villadiego, Javier, Peñalver, Pablo, Morales, Juan Carlos, Delgado, Mario, and González-Rey, Elena

Abstract

Parkinson’s disease (PD) is a complex disorder characterized by the impairment of the dopaminergic nigrostriatal system. PD has duplicated its global burden in the last few years, becoming the leading neurological disability worldwide. Therefore, there is an urgent need to develop innovative approaches that target multifactorial underlying causes to potentially prevent or limit disease progression. Accumulating evidence suggests that neuroinflammatory responses may play a pivotal role in the neurodegenerative processes that occur during the development of PD. Cortistatin is a neuropeptide that has shown potent anti-inflammatory and immunoregulatory effects in preclinical models of autoimmune and neuroinflammatory disorders. The goal of this study was to explore the therapeutic potential of cortistatin in a well-established preclinical mouse model of PD induced by acute exposure to the neurotoxin 1-methil-4-phenyl1-1,2,3,6-tetrahydropyridine (MPTP). We observed that treatment with cortistatin mitigated the MPTP-induced loss of dopaminergic neurons in the substantia nigra and their connections to the striatum. Consequently, cortistatin administration improved the locomotor activity of animals intoxicated with MPTP. In addition, cortistatin diminished the presence and activation of glial cells in the affected brain regions of MPTP-treated mice, reduced the production of immune mediators, and promoted the expression of neurotrophic factors in the striatum. In an in vitro model of PD, treatment with cortistatin also demonstrated a reduction in the cell death of dopaminergic neurons that were exposed to the neurotoxin. Taken together, these findings suggest that cortistatin could emerge as a promising new therapeutic agent that combines anti-inflammatory and neuroprotective properties to regulate the progression of PD at multiple levels.

Published
2024

34. CARMENES input catalog of M dwarfs: VII. New rotation periods for the survey stars and their correlations with stellar activity

Author

Shan, Yutong, Revilla, Daniel, Skrzypinski, Sebastian L., Dreizler, Stefan, Bejar, Victor J. S., Caballero, Jose A., Guillen, Carlos Cardona, Cifuentes, Carlos, Fuhrmeister, Birgit, Reiners, Ansgar, Vanaverbeke, Siegfried, Ribas, Ignasi, Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Francisco J., Casanova, Victor, Cortes-Contreras, Miriam, Dubois, Franky, Gorrini, Paula, Henning, Thomas, Herrero, Enrique, Jeffers, Sandra V., Kemmer, Jonas, Lalitha, Sairam, Lodieu, Nicolas, Logie, Ludwig, Gonzalez, Maria J. Lopez, Martin-Ruiz, Susanna, Montes, David, Morales, Juan Carlos, Nagel, Evangelos, Palle, Enric, Perdelwitz, Volker, Perez-Torres, Miguel, Pollacco, Don, Rau, Steve, Lopez, Cristina Rodriguez, Rodriguez, Eloy, Schoefer, Patrick, Seifert, Walter, Sota, Alfredo, Osorio, Maria Rosa Zapatero, Zechmeister, Mathias, Shan, Yutong, Revilla, Daniel, Skrzypinski, Sebastian L., Dreizler, Stefan, Bejar, Victor J. S., Caballero, Jose A., Guillen, Carlos Cardona, Cifuentes, Carlos, Fuhrmeister, Birgit, Reiners, Ansgar, Vanaverbeke, Siegfried, Ribas, Ignasi, Quirrenbach, Andreas, Amado, Pedro J., Aceituno, Francisco J., Casanova, Victor, Cortes-Contreras, Miriam, Dubois, Franky, Gorrini, Paula, Henning, Thomas, Herrero, Enrique, Jeffers, Sandra V., Kemmer, Jonas, Lalitha, Sairam, Lodieu, Nicolas, Logie, Ludwig, Gonzalez, Maria J. Lopez, Martin-Ruiz, Susanna, Montes, David, Morales, Juan Carlos, Nagel, Evangelos, Palle, Enric, Perdelwitz, Volker, Perez-Torres, Miguel, Pollacco, Don, Rau, Steve, Lopez, Cristina Rodriguez, Rodriguez, Eloy, Schoefer, Patrick, Seifert, Walter, Sota, Alfredo, Osorio, Maria Rosa Zapatero, and Zechmeister, Mathias

Abstract

Abridged: We measured photometric and spectroscopic $P_{\rm rot}$ for a large sample of nearby bright M dwarfs with spectral types from M0 to M9, as part of our continual effort to fully characterize the Guaranteed Time Observation programme stars of the CARMENES survey. We determine $P_{\rm rot}$ for 129 stars. Combined with the literature, we tabulate $P_{\rm rot}$ for 261 stars, or 75% of our sample. We evaluate the plausibility of all periods available for this sample by comparing them with activity signatures and checking for consistency between multiple measurements. We find that 166 of these stars have independent evidence that confirmed their $P_{\rm rot}$. There are inconsistencies in 27 periods, which we classify as debated. A further 68 periods are identified as provisional detections that could benefit from independent verification. We provide an empirical relation for the $P_{\rm rot}$ uncertainty as a function of the $P_{\rm rot}$ value, based on the dispersion of the measurements. We show that published formal errors seem to be often underestimated for periods $\gtrsim 10$ d. We highlight the importance of independent verification on $P_{\rm rot}$ measurements, especially for inactive M dwarfs. We examine rotation-activity relations with emission in X-rays, H$\alpha$, Ca II H & K, and surface magnetic field strengths. We find overall agreement with previous works, as well as tentative differences in the partially versus fully convective subsamples. We show $P_{\rm rot}$ as a function of stellar mass, age, and galactic kinematics. With the notable exception of three transiting planet systems and TZ Ari, all known planet hosts in this sample have $P_{\rm rot} \gtrsim 15$ d. This indicates that important limitations need to be overcome before the radial velocity technique can be routinely used to detect and study planets around young and active stars., Comment: Accepted for publication in A&A

Published
2024

35. Modelling the photosphere of active stars for planet detection and characterization

Author

Herrero, Enrique, Ribas, Ignasi, Jordi, Carme, Morales, Juan Carlos, Perger, Manuel, and Rosich, Albert

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Stellar activity patterns are responsible for jitter effects that are observed at different timescales and amplitudes. These effects are currently in the focus of many exoplanet search projects, since the lack of a well-defined characterization and correction strategy hampers the detection of the signals associated with small exoplanets. Accurate simulations of the stellar photosphere can provide synthetic time series data. These may help to investigate the relation between activity jitter and stellar parameters when considering different active region patterns. Moreover, jitters can be analysed at different wavelength scales in order to design strategies to remove or minimize them. In this work we present the StarSim tool, which is based on a model for a spotted rotating photosphere built from the integration of the spectral contribution of a fine grid of surface elements. The model includes all significant effects affecting the flux intensities and the wavelength of spectral features produced by active regions and planets. A specific application for the characterization and modelling of the spectral signature of active regions is considered, showing that the chromatic effects of faculae are dominant for low temperature contrasts of spots. Synthetic time series are modelled for HD 189733. Our algorithm reproduces both the photometry and the RVs to good precision, generally better than the studies published to date. We evaluate the RV signature of the activity in HD 189733 by exploring a grid of solutions from the photometry. We find that the use of RV data in the inverse problem could break degeneracies and allow for a better determination of some stellar and activity parameters. In addition, the effects of spots are studied for a set of simulated transit photometry, showing that these can introduce variations which are very similar to the signal of an atmosphere dominated by dust., Comment: 19 pages, 13 figures

Published
2015
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39. Perturbações na experiência corporal e experiência de si na solidão crônica.

Author

Williges, Flavio and Ávila Morales, Juan Carlos

Subjects
PHILOSOPHICAL literature, POST-traumatic stress, PHILOSOPHY of emotions, INTIMACY (Psychology), PSYCHOLOGICAL research, LONELINESS
Abstract

Copyright of Revista de Filosofía UIS is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2024
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44. Cortistatin as a Novel Multimodal Therapy for the Treatment of Parkinson’s Disease

Author

Serrano-Martínez, Ignacio, primary, Pedreño, Marta, additional, Castillo-González, Julia, additional, Ferraz-de-Paula, Viviane, additional, Vargas-Rodríguez, Pablo, additional, Forte-Lago, Irene, additional, Caro, Marta, additional, Campos-Salinas, Jenny, additional, Villadiego, Javier, additional, Peñalver, Pablo, additional, Morales, Juan Carlos, additional, Delgado, Mario, additional, and González-Rey, Elena, additional

Published
2024
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46. Generation of an optimal target list for the Exoplanet Characterisation Observatory (EChO)

Author

Varley, Ryan, Waldmann, Ingo, Pascale, Enzo, Tessenyi, Marcell, Hollis, Morgan, Morales, Juan Carlos, Tinetti, Giovanna, Swinyard, Bruce, Deroo, Pieter, Ollivier, Marc, and Micela, Giusi

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

The Exoplanet Characterisation Observatory (EChO) has been studied as a space mission concept by the European Space Agency in the context of the M3 selection process. Through direct measurement of the atmospheric chemical composition of hundreds of exoplanets, EChO would address fundamental questions such as: What are exoplanets made of? How do planets form and evolve? What is the origin of exoplanet diversity? More specifically, EChO is a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planetary sample within its four to six year mission lifetime. In this paper we use the end-to-end instrument simulator EChOSim to model the currently discovered targets, to gauge which targets are observable and assess the EChO performances obtainable for each observing tier and time. We show that EChO would be capable of observing over 170 relativity diverse planets if it were launched today, and the wealth of optimal targets for EChO expected to be discovered in the next 10 years by space and ground-based facilities is simply overwhelming. In addition, we build on previous molecular detectability studies to show what molecules and abundances will be detectable by EChO for a selection of real targets with various molecular compositions and abundances. EChO's unique contribution to exoplanetary science will be in identifying the main constituents of hundreds of exoplanets in various mass/temperature regimes, meaning that we will be looking no longer at individual cases but at populations. Such a universal view is critical if we truly want to understand the processes of planet formation and evolution in various environments. In this paper we present a selection of key results. The full results are available online (http://www.ucl.ac.uk/exoplanets/echotargetlist/)., Comment: Accepted for publication in Experimental Astronomy, 20 pages, 10 figures, 3 tables

Published
2014
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48. Defying the Statistics: Latinx Students' Journeys from ESL to the Honors College at the Community College

Author

Morales, Juan Carlos

Abstract

This qualitative study explored the factors that contributed to the success of community colleges students who completed the English for Academic Purposes (EAP) program for English Language Learners (ELLs) and entered the Honors College at Miami Dade College. The purpose of this study was to develop a mid-level theory about the factors and processes that facilitate the success of these students. A phenomenological and grounded theory approach and analysis was used to discover the lived experiences of these students and to construct a mid-level theory that helps capture their success experiences. The study was conducted at a mid-size campus of a large, Hispanic-serving mostly two-year institution (HSI) located in Southeastern Florida. Data was gathered from students using a one-on-one, semi-structured interview format designed to identify the factors that contributed to student success in navigating their journey from the EAP program to the honors college. The major themes and processes that led to the students' successes are explicated from their interview data. Implications of the study including findings for community college administrators, Honors College administrators, faculty and support services are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]

Published
2018

49. Weighing stars from birth to death: mass determination methods across the HRD

Author

Serenelli, Aldo, Weiss, Achim, Aerts, Conny, Angelou, George C., Baroch, David, Bastian, Nate, Beck, Paul G., Bergemann, Maria, Bestenlehner, Joachim M., Czekala, Ian, Elias-Rosa, Nancy, Escorza, Ana, Van Eylen, Vincent, Feuillet, Diane K., Gandolfi, Davide, Gieles, Mark, Girardi, Léo, Lebreton, Yveline, Lodieu, Nicolas, Martig, Marie, Miller Bertolami, Marcelo M., Mombarg, Joey S. G., Morales, Juan Carlos, Moya, Andrés, Nsamba, Benard, Pavlovski, Krešimir, Pedersen, May G., Ribas, Ignasi, Schneider, Fabian R. N., Silva Aguirre, Victor, Stassun, Keivan G., Tolstoy, Eline, Tremblay, Pier-Emmanuel, and Zwintz, Konstanze

Published
2021
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