Mon. Not. R. Astron. Soc., 491, 4829-4842 (2020/February-1)
High-resolution spectroscopy of the high-velocity hot post-AGB star IRAS 18379-1707 (LS 5112).
IKONNIKOVA N.P., PARTHASARATHY M., DODIN A.V., HUBRIG S. and SARKAR G.
Abstract (from CDS):
The high-resolution (R 48 000) optical spectrum of the B-type supergiant LS 5112, identified as the optical counterpart of the post-AGB candidate IRAS 18379-1707 is analysed. We report the detailed identifications of the observed absorption and emission features in the wavelength range 3700-9200 Å for the first time. The absorption line spectrum has been analysed using non-LTE model atmosphere techniques to determine stellar atmospheric parameters and chemical composition. We estimate Teff = 18 000 ± 1000 K, log g = 2.25 ± 0.08, ξt = 10 ± 4 km s-1, and vsin i = 37 ± 6 km s-1, and the derived abundances indicate a metal-deficient ([M/H] ≃ -0.6) post-AGB star. Chemical abundances of eight different elements were obtained. The estimates of the CNO abundances in IRAS 18379-1707 indicate that these elements are overabundant with [(C + N + O)/S] = + 0.5 ± 0.2 suggesting that the products of helium burning have been brought to the surface as a result of third dredge-up on the AGB. From the absorption lines, we derived heliocentric radial velocity of Vr = -124.0 ± 0.4 km s-1. We have identified permitted emission lines of O I, N I, Na I, S II, Si II, C II, Mg II, and Fe III. The nebula forbidden lines of [N I], [O I], [Fe II], [N II], [S II], [Ni II], and [Cr II] have also been identified. The Balmer lines H α, H β, and H γ show P-Cygni behaviour clearly indicating post-AGB mass-loss process in the object with the wind velocity up to 170 km s-1.
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
stars: abundances - stars: AGB and post-AGB - stars: atmospheres - stars: early-type - stars: evolution - stars: individual: IRAS 18379-1707 - 62 Ori
Status at CDS
Large table(s) will be appraised for possible ingestion in VizieR.
View the reference in ADS
To bookmark this query, right click on this link: simbad:2020MNRAS.491.4829I and select 'bookmark this link' or equivalent in the popup menu