zeta(2) Reticuli, its debris disk, and its lonely stellar companion zeta(1) Ret Different T-c trends for different spectra

• Type: Article in International Scientific Journal
• Date: 2016

Authors

Adibekyan, V (Author) Other; Delgado Mena, E (Author) Other; Figueira, P (Author) Other; Sousa, SG (Author) FCUP; N.C. Santos (Author) FCUP; Faria, JP (Author) Other; Gonzalez Hernandez, JIG (Author) Other; Israelian, G (Author) Other; Harutyunyan, G (Author) Other; Suarez Andres, L (Author) Other; Hakobyan, AA (Author) Other

Journal

Title: Astronomy and Astrophysics

Vol. 591

Final page: A34

ISSN: 0004-6361

Publisher: EDP Sciences

Indexing

ISI Web of Knowledge - 18 Citations

Scopus - 23 Citations

Other information

Authenticus ID: P-00K-JW3

DOI: 10.1051/0004-6361/201628453

Abstract (EN): Context. Several studies have reported a correlation between the chemical abundances of stars and condensation temperature (known as T-c trend). Very recently, a strong T-c trend was reported for the zeta Reticuli binary system, which consists of two solar analogs. The observed trend in zeta(2) Ret relative to its companion was explained by the presence of a debris disk around zeta(2) Ret. Aims. Our goal is to re-evaluate the presence and variability of the T-c trend in the zeta Reticuli system and to understand the impact of the presence of the debris disk on a star. Methods. We used very high-quality spectra of the two stars retrieved from the HARPS archive to derive very precise stellar parameters and chemical abundances. We derived the stellar parameters with the classical (nondifferential) method, while we applied a differential line-by-line analysis to achieve the highest possible precision in abundances, which are fundamental to explore for very tiny differences in the abundances between the stars. Results. We confirm that the abundance difference between zeta(2) Ret and zeta(1) Ret shows a significant (similar to 2 sigma) correlation with T-c. However, we also find that the T-c trends depend on the individual spectrum used (even if always of very high quality). In particular, we find significant but varying differences in the abundances of the same star from different individual high-quality spectra. Conclusions. Our results for the zeta Reticuli system show, for example, that nonphysical factors, such as the quality of spectra employed and errors that are not accounted for, can be at the root of the T-c trends for the case of individual spectra.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11