@Article{AlmeidaDamRodPerJab:2017:HWViSy,
author = "Almeida, L. A. and Damineli, A. and Rodrigues, Cl{\'a}udia Vilega
and Pereira, Marildo Geraldete and Jablonski, Francisco",
affiliation = "{Universidade de S{\~a}o Paulo (USP)} and {Universidade de
S{\~a}o Paulo (USP)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Universidade Estadual de Feira de Santana}
and {Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "HS-2231+2441: an HW Vir system composed of a low-mass white dwarf
and a brown dwarf-",
journal = "Monthly Notices of the Royal Astronomical Society",
year = "2017",
volume = "472",
number = "3",
pages = "3093--3100",
keywords = "Estrelas bin{\'a}rias, Estrelas Quentes, Espectroscopia
{\'o}ptica, Fotometria.",
abstract = "HW Vir systems are rare evolved eclipsing binaries composed of a
hot compact star and a low-mass main sequence star in a close
orbit. These systems provide a direct way to measure the
fundamental properties, e.g. masses and radii, of their
components, hence they are crucial in studying the formation of
subdwarf B stars and low-mass white dwarfs, the commonenvelope
phase and the pre-phase of cataclysmic variables. Here, we present
a detailed study of HS 2231+2441, an HW Vir type system, by
analysing BVRCIC photometry and phaseresolved optical
spectroscopy. The spectra of this system, which are dominated by
the primary component features, were fitted using non-local
thermodynamic equilibrium models providing an effective
temperature Teff = 28 500 ± 500 K, surface gravity log g = 5.40 ±
0.05 cm s\−2 and helium abundance log (n(He)/n(H)) =
\−2.52 ± 0.07. The geometrical orbit and physical
parameters were derived by simultaneously modelling the
photometric and spectroscopic data using the WilsonDevinney code.
We derive two possible solutions for HS 2231+2441 that provide the
component masses: M1 = 0.19 Mand M2 = 0.036 Mor M1 = 0.288 M and
M2 = 0.046 M. Considering the possible evolutionary channels for
forming a compact hot star, the primary of HS 2231+2441 probably
evolved through the red-giant branch scenario and does not have a
helium-burning core, which is consistent with a low-mass white
dwarf. Both solutions are consistent with a brown dwarf as the
secondary. Ke.",
doi = "10.1093/mnras/stx2150",
url = "http://dx.doi.org/10.1093/mnras/stx2150",
issn = "0035-8711 and 1365-2966",
label = "lattes: 9527193250756102 3 AlmeidaDamRodPerJab:2017:HWViSy",
language = "en",
targetfile = "almeida_hs.pdf",
urlaccessdate = "26 abr. 2024"
}