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

Volatile and refractory abundances of F- and G-type stars

J. I. González Hernández, E. Delgado Mena, S. G. Sousa, G. Israelian, N. C. Santos, S. Udry

We present a detailed chemical abundance analysis of a sample of F- and G-type stars. We investigate the possibility that the presence of terrestrial planets could affect the volatile-to-refractory abundance ratios. Stars with and without planets exhibit very similar abundance behaviours, either for solar twins or even when considering the whole sample of 95 solar analogs, 33 with and 62 without detected planets, in the metallicity range -0.3 < [Fe/H] < 0.5. After removing the Galactic chemical evolution effects, the small differences in the abundance patterns of stars with and without planets practically disappear and the mean volatile-to-refractory abundance ratios of the two samples are very close to solar values. If the depletion signature depends on the size of the convective zone, then stars hotter than the Sun should, in principle, show enhanced volatile-to-refractory abundance differences. Thus, we have also selected a sample of late F- and early G-type main-sequence stars with high-quality spectra. We have in total 29 planet-host stars and 32 stars without planets in the Teff range 5950–6400 K. We find very accurate Galactic chemical trends of these hotter stars that match those of solar analogs. Finally, we compare the abundance ratios of volatile and refractory elements versus the condensation temperature of this sample of main-sequence stars hotter than the Sun with respect to those of solar analogs, paying special attention to those stars containing super-Earth-like planets.

planetary systems – stars: abundances – stars: atmospheres

Based on HARPS/3.6m-ESO, UVES/8m-VLT and UES/4.2m-WHT spectroscopic data.

Astronomische Nachrichten
Volume 334, Page 172
February 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