Examinando por Autor "Carleo, I."

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Acceso Abierto
The GAPS Programme at TNG XXI. A GIARPS case study of known young planetary candidates: confirmation of HD 285507 b and refutation of AD Leonis b
(EDP Sciences, 2020-05-29) Carleo, I.; Malavolta, L.; Lanza, A. F.; Damasso, M.; Desidera, S.; Borsa, F.; Mallonn, M.; Pinamonti, M.; Gratton, R.; Alei, E.; Benatti, S.; Mancini, L.; Maldonado, J.; Biazzo, K.; Esposito, M.; Frustagli, G.; González Álvarez, E.; Micela, G.; Scandariato, G.; Sozzatti, A.; Affer, L.; Bignamini, A.; Bonomo, A. S.; Claudi, R.; Cosentino, R.; Covino, E.; Fiorenzano, A. F. M.; Giacobbe, P.; Harutyunyan, A.; Leto, G.; Maggio, A.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Piotto, G.; Poretti, E.; Rainer, M.; Redfield, S.; Baffa, C.; Baruffolo, A.; Buschschacher, N.; Billoti, V.; Cecconi, M.; Falcini, G.; Fantinel, D.; Fini, L.; Galli, A.; Ghedina, A.; Ghinassi, F.; Giani, E.; Guerra, J.; Hernández Díaz, M.; Hernández, N.; Luzzolino, M.; Lodi, M.; Oliva, E.; Origlia, L.; Pérez Ventura, H.; Puglisi, A.; Riverol, C.; Riverol, L.; San Juan, J.; Sanna, N.; Scuderi, S.; Seemann, U.; Sozzi, M.; Tozzi, P.; González Hernández, Carmen; Jimeno González, María; Agenzia Spaziale Italiana (ASI); European Commission (EC); Claudi, R. [0000-0001-7707-5105]; Leto, G. [0000-0002-0040-5011]; Piotto, G. [0000-0002-9937-6387]; Bonomo, A. S. [0000-0002-6177-198X]; Sozzetti, A. [0000-0002-7504-365X]; Biazzo, K. [0000-0002-1892-2180]; Ghedina, A. [0000-0003-4702-5152]; Damasso, M. [0000-0001-9984-4278]; Cosentino, R. [0000-0003-1784-1431]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. The existence of hot Jupiters is still not well understood. Two main channels are thought to be responsible for their current location: a smooth planet migration through the protoplanetary disk or the circularization of an initial highly eccentric orbit by tidal dissipation leading to a strong decrease in the semimajor axis. Different formation scenarios result in different observable effects, such as orbital parameters (obliquity and eccentricity) or frequency of planets at different stellar ages. Aims. In the context of the GAPS Young Objects project, we are carrying out a radial velocity survey with the aim of searching and characterizing young hot-Jupiter planets. Our purpose is to put constraints on evolutionary models and establish statistical properties, such as the frequency of these planets from a homogeneous sample. Methods. Since young stars are in general magnetically very active, we performed multi-band (visible and near-infrared) spectroscopy with simultaneous GIANO-B + HARPS-N (GIARPS) observing mode at TNG. This helps in dealing with stellar activity and distinguishing the nature of radial velocity variations: stellar activity will introduce a wavelength-dependent radial velocity amplitude, whereas a Keplerian signal is achromatic. As a pilot study, we present here the cases of two known hot Jupiters orbiting young stars: HD 285507 b and AD Leo b. Results. Our analysis of simultaneous high-precision GIARPS spectroscopic data confirms the Keplerian nature of the variation in the HD 285507 radial velocities and refines the orbital parameters of the hot Jupiter, obtaining an eccentricity consistent with a circular orbit. Instead, our analysis does not confirm the signal previously attributed to a planet orbiting AD Leo. This demonstrates the power of the multi-band spectroscopic technique when observing active stars.
Acceso Abierto
The GAPS programme at TNG XXII. The GIARPS view of the extended helium atmosphere of HD 189733 b accounting for stellar activity
(EDP Sciences, 2020-07-07) Guilluy, G.; Andretta, V.; Borsa, F.; Giacobbe, P.; Sozzetti, A.; Covino, E.; Bourrier, V.; Fossati, L.; Bonomo, A. S.; Esposito, M.; Giampapa, M. S.; Harutyunyan, A.; Rainer, M.; Brogi, M.; Bruno, G.; Claudi, R.; Frustagli, G.; Lanza, A. F.; Mancini, L.; Pino, L.; Poretti, E.; Scandariato, G.; Affer, L.; Baffa, C.; Baruffolo, A.; Benatti, S.; Biazzo, K.; Bignamini, A.; Boschin, W.; Carleo, I.; Cecconi, M.; Cosentino, R.; Damasso, M.; Desidera, S.; Falcini, G.; Martínez Fiorenzano, A. F.; Ghedina, A.; González Álvarez, E.; Guerra, J.; Hernández, N.; Leto, G.; Maggio, A.; Malavolta, L.; Maldonado, J.; Micela, G.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Piotto, G.; Reiners, A.; Agenzia Spaziale Italiana (ASI); Istituto Nazionale di Astrofisica (INAF); Swiss National Science Foundation (SNSF); European Research Council (ERC); Deutsche Forschungsgemeinschaft (DFG); Claudi, R. [orcid.org/0000-0001-7707-5105]; Leto, G. [orcid.org/0000-0002-0040-5011]; Ghedina, A. [orcid.org/0000-0003-4702-5152]; Pino, L. [orcid.org/0000-0002-1321-8856]; Damaso, M. [orcid.org/0000-0001-9984-4278]; Cosentino, R. [orcid.org/0000-0003-1784-1431]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Context. Exoplanets orbiting very close to their parent star are strongly irradiated. This can lead the upper atmospheric layers to expand and evaporate into space. The metastable helium (He I) triplet at 1083.3 nm has recently been shown to be a powerful diagnostic to probe extended and escaping exoplanetary atmospheres. Aims. We perform high-resolution transmission spectroscopy of the transiting hot Jupiter HD 189733 b with the GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo, taking advantage of the simultaneous optical+near infrared spectral coverage to detect He I in the planet’s extended atmosphere and to gauge the impact of stellar magnetic activity on the planetary absorption signal. Methods. Observations were performed during five transit events of HD 189733 b. By comparison of the in-transit and out-of-transit GIANO-B observations, we computed high-resolution transmission spectra. We then used them to perform equivalent width measurements and carry out light-curves analyses in order to consistently gauge the excess in-transit absorption in correspondence with the He I triplet. Results. We spectrally resolve the He I triplet and detect an absorption signal during all five transits. The mean in-transit absorption depth amounts to 0.75 ± 0.03% (25σ) in the core of the strongest helium triplet component. We detect night-to-night variations in the He I absorption signal likely due to the transit events occurring in the presence of stellar surface inhomogeneities. We evaluate the impact of stellar-activity pseudo-signals on the true planetary absorption using a comparative analysis of the He I 1083.3 nm (in the near-infrared) and the Hα (in the visible) lines. Using a 3D atmospheric code, we interpret the time series of the He I absorption lines in the three nights not affected by stellar contamination, which exhibit a mean in-transit absorption depth of 0.77 ± 0.04% (19σ) in full agreement with the one derived from the full dataset. In agreement with previous results, our simulations suggest that the helium layers only fill part of the Roche lobe. Observations can be explained with a thermosphere heated to ~12 000 K, expanding up to ~1.2 planetary radii, and losing ~1 g s−1 of metastable helium. Conclusions. Our results reinforce the importance of simultaneous optical plus near infrared monitoring when performing high-resolution transmission spectroscopy of the extended and escaping atmospheres of hot planets in the presence of stellar activity.