Site Map
Contacts
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

The GAPS programme with HARPS-N at TNG?
I. Observations of the Rossiter-McLaughlin effect and characterisation of the transiting system Qatar-1

E. Covino, M. Esposito, M. Barbieri, L. Mancini, V. Nascimbeni, R. Claudi, S. Desidera, R. Gratton, A. F. Lanza, A. Sozzetti, K. Biazzo, L. Affer, D. Gandolfi, U. Munari, I. Pagano, A. S. Bonomo, A. Collier Cameron, G. Hébrard, A. Maggio, S. Messina, G. Micela, E. Molinari, F. Pepe, G. Piotto, I. Ribas, N. C. Santos, J. Southworth, E. Shkolnik, A. H. M. J. Triaud, L. Bedin, S. Benatti, C. Boccato, M. Bonavita, F. Borsa, L. Borsato, D. Brown, E. Carolo, S. Ciceri, R. Cosentino, M. Damasso, F. Faedi, A. F. Martínez Fiorenzano, D. W. Latham, C. Lovis, C. Mordasini, N. Nikolov, E. Poretti, M. Rainer, R. Rebolo López, G. Scandariato, R. Silvotti, R. Smareglia, J. M. Alcalá, A. Cunial, L. Di Fabrizio, M. P. Di Mauro, P. Giacobbe, V. Granata, H. Avet, C. Knapic, M. Lattanzi, G. Leto, G. Lodato, L. Malavolta, F. Marzari, M. Molinaro, D. Nardiello, M. Pedani, L. Prisinzano, D. Turrini

Abstract
Context. Our understanding of the formation and evolution of planetary systems is still fragmentary because most of the current data provide limited information about the orbital structure and dynamics of these systems. The knowledge of the orbital properties for a variety of systems and at different ages yields information on planet migration and on star-planet tidal interaction mechanisms.
Aims. In this context, a long-term, multi-purpose, observational programme has started with HARPS-N at TNG and aims to characterise the global architectural properties of exoplanetary systems. The goal of this first paper is to fully characterise the orbital properties of the transiting system Qatar-1 as well as the physical properties of the star and the planet.
Methods. We exploit HARPS-N high-precision radial velocity measurements obtained during a transit to measure the Rossiter-McLaughlin effect in the Qatar-1 system, and out-of-transit measurements to redetermine the spectroscopic orbit. New photometric-transit light-curves were analysed and a spectroscopic characterisation of the host star atmospheric parameters was performed based on various methods (line equivalent width ratios, spectral synthesis, spectral energy distribution).
Results. We achieved a significant improvement in the accuracy of the orbital parameters and derived the spin-orbit alignment of the system; this information, combined with the spectroscopic determination of the host star properties (rotation, Teff, log g, metallicity), allows us to derive the fundamental physical parameters for star and planet (masses and radii). The orbital solution for the Qatar-1 system is consistent with a circular orbit and the system presents a sky-projected obliquity of λ = -8.4±7.1 deg. The planet, with a mass of 1.33±0.05 MJ, is found to be significantly more massive than previously reported. The host star is confirmed to be metal-rich ([Fe/H] = 0.20±0.10) and slowly rotating (v sin I = 1.7±0.3 km s-1), though moderately active, as indicated by the strong chromospheric emission in the CaII H&K line cores (log R'HK ≈ -4.60).
Conclusions. We find that the system is well aligned and fits well within the general λ versus Teff trend. We can definitely rule out any significant orbital eccentricity. The evolutionary status of the system is inferred based on gyrochronology, and the present orbital configuration and timescale for orbital decay are discussed in terms of star-planet tidal interactions.

Keywords
techniques: radial velocities – stars: late-type – stars: fundamental parameters – stars: individual: Qatar-1

Notes
Based on observations collected at the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the Fundación Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, in the frame of the programme Global Architecture of Planetary Systems (GAPS).
Also based on observations collected at Asiago Observatory, and Calar Alto Observatory.
Full Table 3 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/554/A28

Astronomy and Astrophysics
Volume 554, Page A28_1
June 2013

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website