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

Photodynamical mass determination of the multiplanetary system K2-19

S. C. C. Barros, J. -M. Almenara, O. Demangeon, M. Tsantaki, A. Santerne, D. J. Armstrong, D. Barrado y Navascues, D. J. A. Brown, M. Deleuil, J. Lillo Box, H. P. Osborn, D. Pollacco, L. Abe, Ph. André, P. Bendjoya, I. Boisse, A. S. Bonomo, F. Bouchy, G. Bruno, J. Rey Cerda, B. Courcol, R. F. Díaz, G. Hébrard, J. Kirk, J. C. Lachurié, K. W. F. Lam, P. Martinez, J. McCormac, C. Moutou, A. S. Rajpurohit, J.-P. Rivet, J. Spake, O. Suarez, D. Toublanc, S. R. Walker

Abstract
K2-19 is the second multiplanetary system discovered with K2 observations. The system is composed of two Neptune size planets close to the 3:2 mean-motion resonance. To better characterize the system we obtained two additional transit observations of K2-19b and five additional radial velocity observations. These were combined with K2 data and fitted simultaneously with the system dynamics (photodynamical model) which increases the precision of the transit time measurements. The higher transit time precision allows us to detect the chopping signal of the dynamic interaction of the planets that in turn permits to uniquely characterize the system. Although the reflex motion of the star was not detected, dynamic modelling of the system allowed us to derive planetary masses of Mb = 44 ± 12  M and Mc = 15.9 ± 7.0  M for the inner and the outer planets, respectively, leading to densities close to Uranus. We also show that our method allows the derivation of mass ratios using only the 80 d of observations during the first campaign of K2.

Keywords
techniques: photometric - techniques: radial velocities - time - planets and satellites: detection - planets and satellites: dynamical evolution and stability - planets and satellites: individual: EPIC201505350, K2-19

Monthly Notices of the Royal Astronomical Society
Volume 454, Page 4267
December 2015

>> 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