The GAPS Programme at TNG XXI -- A GIARPS case-study of known young planetary candidates: confirmation of HD 285507 b and refutation of AD Leo b
Creators: name: Carleo, I.
name: Malavolta, L.
name: Lanza, A. F.
name: Damasso, M.
name: Desidera, S.
name: Borsa, F.
name: Mallonn, M.
name: Pinamonti, M.
name: Gratton, R.
name: Alei, E.
name: Benatti, S.
name: Mancini, L.
name: Maldonado, J.
name: Biazzo, K.
name: Esposito, M.
name: Frustagli, G.
name: González-Álvarez, E.
name: Micela, G.
name: Scandariato, G.
name: Sozzetti, A.
name: Affer, L.
name: Bignamini, A.
name: Bonomo, A. S.
name: Claudi, R.
name: Cosentino, R.
name: Covino, E.
name: Fiorenzano, A. F. M.
name: Giacobbe, P.
name: Harutyunyan, A.
name: Leto, G.
name: Maggio, A.
name: Molinari, E.
name: Nascimbeni, V.
name: Pagano, I.
name: Pedani, M.
name: Piotto, G.
name: Poretti, E.
name: Rainer, M.
name: Redfield, S.
name: Baffa, C.
name: Baruffolo, A.
name: Buchschacher, N.
name: Billotti, V.
name: Cecconi, M.
name: Falcini, G.
name: Fantinel, D.
name: Fini, L.
name: Galli, A.
name: Ghedina, A.
name: Ghinassi, F.
name: Giani, E.
name: Gonzalez, C.
name: Gonzalez, M.
name: Guerra, J.
name: Diaz, M. Hernandez
name: Hernandez, N.
name: Iuzzolino, M.
name: Lodi, M.
name: Oliva, E.
name: Origlia, L.
name: Ventura, H. Perez
name: Puglisi, A.
name: Riverol, C.
name: Riverol, L.
name: Juan, J. San
name: Sanna, N.
name: Scuderi, S.
name: Seemann, U.
name: Sozzi, M.
name: Tozzi, A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: 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 proto-planetary disk or the circularization of an initial high eccentric orbit by tidal dissipation leading to a strong decrease of the semimajor axis. Different formation scenarios result in different observable effects, such as orbital parameters (obliquity/eccentricity), or frequency of planets at different stellar ages. In the context of the GAPS Young-Objects project, we are carrying out a radial velocity survey with the aim to search and characterize 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. 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 to deal with stellar activity and distinguish 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 already claimed hot Jupiters orbiting young stars: HD285507 b and AD Leo b. Our analysis of simultaneous high-precision GIARPS spectroscopic data confirms the Keplerian nature of HD285507's radial velocities variation and refines the orbital parameters of the hot Jupiter, obtaining an eccentricity consistent with a circular orbit. On the other hand, 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.