HD 191110 a SB2 system with HgMn and Hg components

Abstract

Abstract. In this paper we present the first quantitative abundance analysis of the SB2 system with HgMn and Hg components HD 191110. Time-resolved (R = 14 000) spectroscopic observations of this system have been obtained during September and October 2002 at the Catania Astrophysical Observatory. Combining these observations with spectra (R = 50 000-110 000) taken from the CFHT archive, we refined the orbital period of this system (P = 9.34661 ± 0.00002 d) and then we recalculated the fundamental parameters characterizing its orbit. From the fit of the H β profiles, obtained at different orbital phases, we determined the effective temperatures and surface gravities of each component and the light ratio: T A eff = 11 000 K, log g A = 3.60, T B eff = 10 700 K, log g B = 3.90, L A /L B = 1.20. Regarding the chemical composition, both components have solar abundances of sulfur, titanium and iron; magnesium and silicon are slightly underabundant; platinum and yttrium are overabundant. Manganese lines have been detected only in the spectrum of the primary. As to rare-earths, two lines of Nd have been identified in the secondary's spectrum. Other lines we identified in our spectra belong to P, Cr, Ni, Sr, Zr and Au. We also discuss the isotopic structure of the Hg λ3983.9 Å line.

Orbital solutions for SB2 systems with a HgMn component

“…Systematic errors have been estimated in Catanzaro et al (2003), 2.50 ± 1.37 km s −1 . At the beginning of 2003, because of the change in the resolving power of the spectrograph, we needed to re-evaluate the errors.…”

“…In one spectrum of HD 173524 taken at CFHT (HJD = 2449968.7765) the stars were close to conjunction, so the previous procedure could not be applied. To determine the radial velocity we modeled the observed spectrum as described in Catanzaro et al (2003). Photospheric parameters have been adopted from Adelman et al (1998).…”

“…This system has been recently studied by Catanzaro et al (2003). The authors determined the orbital parameters (reported here again in Table 3) and they also performed a detailed abundance analysis.…”

“…Considering a possible indetermination in the radius of 0.5 R and v e sin i = 7 km s −1 for both components (Catanzaro et al 2003), the inclination of the orbit ranges between 21 and 41 degrees. This result is compatible with the angle of 35…”

“…To deal with homogeneous data sets, we selected all the SB2 systems reported in the catalogue of HgMn stars compiled by Schneider (1981) (23 out of 127 stars). In this paper we present and discuss the results for the first seven orbits, including the SB2 system HD 191110 recently published in Catanzaro et al (2003).…”