Rho Puppis: some spectroscopic results or ''The Taming of Rho Puppis''

Autor(en)

Victoria Antoci, Nicole Nesvacil, Gerald Handler

Abstrakt

Basic parameters such as Teff and log g as well as the projected rotational velocity v sin i for the Delta Scuti star Rho Puppis were redetermined, using high resolution and high S/N spectra from the ESO Science Archive (program ID 60.A-9036(A)). The data were obtained with the HARPS spectrograph attached to the ESO La Silla 3.6m telescope in 2006. For a preliminary analysis of atmospheric parameters and chemical abundances we used a spectral range between 4500 and 5800 ? A. Equivalent widths for 33 Fe I and for 8 Fe I I lines were measured. The best result for Teff is 6900 ± 150 K, corresponding to reported values in literature (Burkhart & Coupry 1991). The surface gravity log g resulted in 3.8 ± 0.2 adjusted from the Fe I and Fe I I ionisation equilibrium. The projected rotational velocity v sin i was found to be 14.0 ± 1.5 kms -1 . For a detailed description of the procedure applied in this work for abundance analysis and for the codes and software packages used, see Stuetz et al. (2006) and Fossati et al. (2008) and references therein. Rho Puppis was the target of a five night long observing run at the AAT (Anglo Australian Telescope) in January 2008. Using UCLES, we gathered around 1200 high resolution high S/N spectra. Preliminary analysis revealed one frequency at 7.10 c/d, which was identified as the radial fundamental mode1 (Zima 2008), as already reported by Mathias et al. (1997). Also significant in the frequency spectrum is the first harmonic, which clearly shows the nonlinear behaviour of the main mode, having a very high amplitude of pulsation. There is evidence for further pulsational frequencies in Rho Puppis, but the time base of our data set is not long enough for more detailed frequency analyses in the Delta Scuti regime. Rho Puppis, an evolved Fm star eponymous for a whole chemically peculiar subgroup of the Delta Scuti stars, was selected as target for testing the theory predicting solar-like oscillations in cool Delta Scuti stars (Houdek et al. 1999; Samadi et al. 2002). From the observational point of view, no attempts to measure solar-like oscillations in such hot stars have been made so far.

Organisation(en)

Institut für Astrophysik

Journal

Communications in Asteroseismology

Band

157

Seiten

286-287

Anzahl der Seiten

2

ISSN

1021-2043

Publikationsdatum

2008

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/1c28e5c7-d28d-4875-916a-74f4ad1d3964