It takes two planets in resonance to tango around K2-146
| Autor: | Lam, Kristine W. F., Korth, Judith, Masuda, Kento, Csizmadia, Szilárd, Eigmüller, Philipp, Stefánsson, Guðmundur Kári, Endl, Michael, Albrecht, Simon, Luque, Rafael, Livingston, John H., Hirano, Teruyuki, Sobrino, Roi Alonso, Barragán, Oscar, Cabrera, Juan, Carleo, Ilaria, Chaushev, Alexander, Cochran, William D., Dai, Fei, de Leon, Jerome, Deeg, Hans J., Erikson, Anders, Esposito, Massimiliano, Fridlund, Malcolm, Fukui, Akihiko, Gandolfi, Davide, Georgieva, Iskra, Cuesta, Lucá Gonzalez, Grziwa, Sascha, Guenther, Eike W., Hatzes, Artie P., Hidalgo, Diego, Hjorth, Maria, Kabath, Petr, Knudstrup, Emil, Lund, Mikkel N., Mahadevan, Suvrath, Mathur, Savita, Rodríguez, Pilar Montañes, Murgas, Felipe, Narita, Norio, Nespral, David, Niraula, Prajwal, Palle, Enric, Pätzold, Martin, Persson, Carina M., Prieto-Arranz, Jorge, Rauer, Heike, Redfield, Seth, Ribas, Ignasi, Robertson, Paul, Skarka, Marek, Smith, Alexis M. S., Subjak, Jan, Van Eylen, Vincent |
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| Rok vydání: | 2019 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.3847/1538-3881/ab66c9 |
| Popis: | K2-146 is a cool, 0.358 M_sun dwarf that was found to host a mini-Neptune with a 2.67-days period. The planet exhibited strong transit timing variations (TTVs) of greater than 30 minutes, indicative of the presence of a further object in the system. Here we report the discovery of the previously undetected outer planet, K2-146 c, in the system using additional photometric data. K2-146 c was found to have a grazing transit geometry and a 3.97-day period. The outer planet was only significantly detected in the latter K2 campaigns presumably because of precession of its orbital plane. The TTVs of K2-146 b and c were measured using observations spanning a baseline of almost 1200 days. We found strong anti-correlation in the TTVs, suggesting the two planets are gravitationally interacting. Our TTV and transit model analyses revealed that K2-146 b has a radius of 2.25 $\pm$ 0.10 \R_earth and a mass of 5.6 $\pm$ 0.7 M_earth, whereas K2-146 c has a radius of $2.59_{-0.39}^{+1.81}$ R_earth and a mass of 7.1 $\pm$ 0.9 M_earth. The inner and outer planets likely have moderate eccentricities of $e = 0.14 \pm 0.07$ and $0.16 \pm 0.07$, respectively. Long-term numerical integrations of the two-planet orbital solution show that it can be dynamically stable for at least 2 Myr. The evaluation of the resonance angles of the planet pair indicates that K2-146 b and c are likely trapped in a 3:2 mean motion resonance. The orbital architecture of the system points to a possible convergent migration origin. Comment: 19 pages with 13 figures and 4 tables; Submitted |
| Databáze: | arXiv |
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