The HARPS search for southern extra-solar planets - IX. exoplanets orbiting HD100777, HD190647, and HD221287

• Type: Article in International Scientific Journal
• Date: 2007

Authors

Naef, D (Author) Other; Mayor, M (Author) Other; Benz, W (Author) Other; Bouchy, F (Author) Other; Lo Curto, G (Author) Other; Lovis, C (Author) Other; Moutou, C (Author) Other; Pepe, F (Author) Other; Queloz, D (Author) Other; N.C. Santos (Author) Other; Udry, S (Author) Other

Journal

Title: Astronomy and Astrophysics

Vol. 470

Pages: 721-U128

ISSN: 0004-6361

Publisher: EDP Sciences

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 27 Citations

Other information

Authenticus ID: P-004-89G

DOI: 10.1051/0004-6361:20077361

Abstract (EN): Context. The HARPS high-resolution high-accuracy spectrograph was made available to the astronomical community in the second half of 2003. Since then, we have been using this instrument for monitoring radial velocities of a large sample of Solar-type stars (similar or equal to 1400 stars) in order to search for their possible low-mass companions. Aims. Amongst the goals of our survey, one is to significantly increase the number of detected extra-solar planets in a volume-limited sample to improve our knowledge of their orbital elements distributions and thus obtain better constraints for planet-formation models. Methods. Radial-velocities were obtained from high-resolution HARPS spectra via the cross-correlation method. We then searched for Keplerian signals in the obtained radial-velocity data sets. Finally, companions orbiting our sample stars were characterised using the fitted orbital parameters. Results. In this paper, we present the HARPS radial-velocity data and orbital solutions for 3 Solar-type stars: HD 100777, HD 190647, and HD 221287. The radial-velocity data of HD 100777 is best explained by the presence of a 1.16 M-Jup planetary companion on a 384-day eccentric orbit (e = 0.36). The orbital fit obtained for the slightly evolved star HD 190647 reveals the presence of a long-period (P = 1038 d) 1.9 MJup planetary companion on a moderately eccentric orbit (e = 0.18). HD 221287 is hosting a 3.1 M-Jup planet on a 456-day orbit. The shape of this orbit is not very well-constrained because of our non-optimal temporal coverage and because of the presence of abnormally large residuals. We find clues that these large residuals result from spectral line-profile variations probably induced by processes related to stellar activity.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8