Dr. Astudillo-Defru, Nicola

2020, Kemmer, J., Stock, S., Kossakowski, D., Kaminski, A., Molaverdikhani, K., Schlecker, M., Caballero, J. A., Amado, P. J., Astudillo-Defru, Nicola, Bonfils, X., Ciardi, David, Collins, Karen A., Espinoza, N., Fukui, A., Hirano, T., Jenkins, J. M., Latham, D. W., Matthews, E. C., Narita, N., Pallé, E., Parviainen, H., Quirrenbach, A., Reiners, A., Ribas, I., Ricker, G., Schlieder, J. E., Seager, S., Vanderspek, R., Winn, J. N., Almenara, José Manuel, Bejar, V. J. S., Bluhm, P., Bouchy, F., Boyd, P., Christiansen, J. L., Cifuentes, C., Cloutier, Ryan, Collins, Kevin I., Cortés Contreras, M., Crossfield, Ian J. M., Crouzet, N., de Leon, J. P., Della Rose, D. D., Delfosse, X., Dreizler, S., Esparza Borges, E., Essack, Z., Forveille, Th., Figueira, P., Galadí Enríquez, D., Gan, T., Glidden, A., Gonzales, E. J., Guerra, P., Harakawa, H., Hatzes, A. P., Henning, Th., Herrero, E., Hodapp, K., Hori, Y., Howell, S. B., Ikoma, M., Isogai, K., Jeffers, S. V., Kürster, M., Kawauchi, K., Kimura, T., Klagyivik, P., Kotani, T., Kurokawa, T., Kusakabe, N., Kuzuhara, M., Lafarga, M., Livingston, J. H., Luque, R., Matson, R., Morales, J. C., Mori, M., Muirhead, P. S., Murgas, F., Nishikawa, J., Nishiumi, T., Omiya, M., Reffert, S., Rodríguez López, C., Santos, N. C., Schöfer, P., Schwarz, R. P., Shiao, B., Tamura, M., Terada, Y., Twicken, J. D., Ueda, A., Vievard, S., Watanabe, N., Zechmeister, M.

We present the confirmation and characterisation of GJ 3473 b (G 50–16, TOI-488.01), a hot Earth-sized planet orbiting an M4 dwarf star, whose transiting signal (P = 1.198 003 5 ± 0.000 001 8 d) was first detected by the Transiting Exoplanet Survey Satellite (TESS). Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, Mb = 1.86 ± 0.30 M⊕, and radius, Rb = 1.264 ± 0.050 R⊕. Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, Mc sin i = 7.41 ± 0.91 M⊕, and orbital period, Pc = 15.509 ± 0.033 d. The inner planet of the system, GJ 3473 b, is one of the hottest transiting Earth-sized planets known thus far, accompanied by a dynamical mass measurement, which makes it a particularly attractive target for thermal emission spectroscopy.

2020, Cloutier, Ryan, Eastman, Jason D., Rodríguez, Joseph E., Astudillo-Defru, Nicola, Bonfils, Xavier, Mortier, Annelies, Watson, Christopher A., Stalport, Manu, Pinamonti, Matteo, Lienhard, Florian, Harutyunyan, Avet, Damasso, Mario, Latham, David W., Collins, Karen A., Massey, Robert, Irwin, Jonathan, Winters, Jennifer G., Charbonneau, David, Ziegler, Carl, Matthews, Elisabeth, Crossfield, Ian J. M., Kreidberg, Laura, Quinn, Samuel N., Ricker, George, Vanderspek, Roland, Seager, Sara, Winn, Joshua, Jenkins, Jon M., Vezie, Michael, Udry, Stéphane, Twicken, Joseph D., Tenenbaum, Peter, Sozzetti, Alessandro, Ségransan, Damien, Schlieder, Joshua E., Sasselov, Dimitar, Santos, Nuno C., Rice, Ken, Rackham, Benjamin V., Poretti, Ennio, Piotto, Giampaolo, Phillips, David, Pepe, Francesco, Molinari, Emilio, Mignon, Lucile, Micela, Giuseppina, Melo, Claudio, De Medeiros, José R., Mayor, Michel, Matson, Rachel A., Martínez Fiorenzano, Aldo F., Mann, Andrew W., Magazzú, Antonio, Lovis, Christophe, López-Morales, Mercedes, López, Eric, Lissauer, Jack J., Lépine, Sébastien, Law, Nicholas, Kielkopf, John F., Johnson, John A., Jensen, Eric L. N., Howell, Steve B., Gonzáles, Erica, Ghedina, Adriano, Forveille, Thierry, Figueira, Pedro, Dumusque, Xavier, Dressing, Courtney D., Doyon, René, Díaz, Rodrigo F., Di Fabrizio, Luca, Delfosse, Xavier, Cosentino, Rosario, Conti, Dennis M., Collins, Kevin I., Collier Cameron, Andrew, Ciardi, David, Caldwell, Douglas A., Burke, Christopher, Buchhave, Lars, Briceño, César, Boyd, Patricia, Bouchy, François, Beichman, Charles, Artigau, Étienne, Almenara, José Manuel

We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, Ks = 8.204, Rs = 0.374 R⊙, Ms = 0.401 M⊙, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of Pb = 0.77, Pc = 12.25 days and sizes rp,b = 1.33 ± 0.07, rp,c = 2.30 ± 0.16 R⊕, the two planets span the radius valley in period–radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of ${m}_{p,b}={2.62}_{-0.46}^{+0.48}$ and ${m}_{p,c}={8.6}_{-1.3}^{+1.6}$ M⊕, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley.

2020, Gan, Tianjun, Shporer, Avi, Livingston, John H., Collins, Karen A., Mao, Shude, Trani, Alessandro A., Gandolf, Davide, Hirano, Teruyuki, Luque, Rafael, Stassun, Keivan G., Ziegler, Carl, Howell, Steve B., Hellier, Coel, Irwin, Jonathan M., Winters, Jennifer G., Anderson, David R., Briceño, César, Law, Nicholas, Mann, Andrew W., Bonfils, Xavier, Astudillo-Defru, Nicola, Jensen, Eric L. N., Anglada Escudé, Guillem, Ricker, George R., Vanderspek, Roland, Latham, David W., Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Furesz, Gabor, Guerrero, Natalia M., Quintana, Elisa, Twicken, Joseph D., Caldwell, Douglas A., Tenenbaum, Peter, Huang, Chelsea X., Rowden, Pamela, Rojas-Ayala, Bárbara

We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the Transiting Exoplanet Survey Satellite (TESS) survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located 29.87 ± 0.02 pc away with a mass of 0.502 ± 0.015 Me and a radius of 0.501 ± 0.030 Re. We validate the planet by combining space- and ground-based photometry, spectroscopy, and imaging. The planet has a radius of 1.088 ± 0.064 R⊕ with a 3σ mass upper limit of 8.7 M⊕. We analyze the galactic kinematics and orbit of the host star LHS 1815 and find that it has a large probability (Pthick/Pthin = 6482) to be in the thick disk with a much higher expected maximal height (Zmax = 1.8 kpc) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using, for example, the upcoming James Webb Space Telescope, can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick disks, thin disks, and halo).

2020, Shporer, Avi, Collins, Karen A., Astudillo-Defru, Nicola, Irwin, Jonathan, Bonfils, Xavier, Collins, Kevin I., Matthews, Elisabeth, Winters, Jennifer G., Anderson, David R., Armstrong, James D., Charbonneau, David, Cloutier, Ryan, Daylan, Tansu, Gan, Tianjun, Günther, Maximilian N., Hellier, Coel, Horne, Keith, Huang, Chelsea X., Jensen, Eric L. N., Kielkopf, John, Palle, Enric, Sefako, Ramotholo, Stassun, Keivan G., Tan, Thiam-Guan, Vanderburg, Andrew, Ricker, George R., Latham, David W., Vanderspek, Roland, Seager, Sara, Winn, Joshua N., Jenkins, Jon M., Colon, Knicole, Dressing, Courtney D., Léepine, Sébastien, Muirhead, Philip S., Rose, Mark E., Twicken, Joseph D., Villaseñor, Jesús Noel

We report the discovery of GJ 1252 b, a planet with a radius of 1.193 ± 0.074 ${R}_{\oplus }$ and an orbital period of 0.52 days around an M3-type star (0.381 ± 0.019 ${M}_{\odot }$, 0.391 ± 0.020 ${R}_{\odot }$) located 20.385 ± 0.019 pc away. We use Transiting Exoplanet Survey Satellite (TESS) data, ground-based photometry and spectroscopy, Gaia astrometry, and high angular resolution imaging to show that the transit signal seen in the TESS data must originate from a transiting planet. We do so by ruling out all false-positive scenarios that attempt to explain the transit signal as originating from an eclipsing stellar binary. Precise Doppler monitoring also leads to a tentative mass measurement of 2.09 ± 0.56 M⊕. The host star proximity, brightness (V = 12.19 mag, K = 7.92 mag), low stellar activity, and the system's short orbital period make this planet an attractive target for detailed characterization, including precise mass measurement, looking for other objects in the system, and planet atmosphere characterization.

2020, Astudillo-Defru, Nicola, Cloutier, Ryan, Wang, S. X., Teske, J., Brahm, R., Hellier, C., Ricker, G., Vanderspek, R., Latham, D., Seager, S., Winn, J. N., Jenkins, J. M., Collins, Karen A., Stassun, K. G., Ziegler, C., Almenara, José Manuel, Anderson, David R., Artigau, Étienne, Bonfils, X., Bouchy, F., Briceño, C., Butler, R. P., Charbonneau, D., Conti, Dennis M., Crane, J., Crossfield, Ian J. M., Davies, M., Delfosse, X., Díaz, R. F., Doyon, R., Dragomir, D., Eastman, J. D., Espinoza, N., Essack, Z., Feng, F., Figueira, P., Forveille, T., Gan, T., Glidden, A., Guerrero, N., Hart, R., Henning, Th., Horch, E. P., Isopi, G., Jenkins, J. S., Jordán, A., Kielkopf, J. F., Law, N., Lovis, C., Mallia, F., Mann, A. W., De Medeiros, J. R., Melo, C., Mennickent, R. E., Mignon, L., Murgas. F., Nusdeo, D. A., Pepe, F., Relles, H. M., Rose, M., Santos, N. C., Ségransan, D., Shectman, S., Shporer, A., Smith, J. C., Torres, P., Udry, S., Villaseñor, J., Winters, J. G., Zhou, G.

We report the detection of a transiting super-Earth-sized planet (R = 1.39 ± 0.09 R⊕) in a 1.4-day orbit around L 168-9 (TOI-134), a bright M1V dwarf (V = 11, K = 7.1) located at 25.15 ± 0.02 pc. The host star was observed in the first sector of the Transiting Exoplanet Survey Satellite (TESS) mission. For confirmation and planet mass measurement purposes, this was followed up with ground-based photometry, seeing-limited and high-resolution imaging, and precise radial velocity (PRV) observations using the HARPS and Magellan/PFS spectrographs. By combining the TESS data and PRV observations, we find the mass of L 168-9 b to be 4.60 ± 0.56 M⊕ and thus the bulk density to be 1.74−0.33+0.44 times higher than that of the Earth. The orbital eccentricity is smaller than 0.21 (95% confidence). This planet is a level one candidate for the TESS mission’s scientific objective of measuring the masses of 50 small planets, and it is one of the most observationally accessible terrestrial planets for future atmospheric characterization.