Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published February 2018 | Published
Journal Article Open

Spectroscopic and Photometric Analysis of the HW Vir Star PTF1 J011339.09+225739.1

Abstract

HW Vir systems are rare eclipsing binary systems including a subdwarf B star (sdB) with a faint companion, mostly M-dwarfs. Up to now, 19 HW Vir systems have been published, three of them with substellar companions. We report the spectroscopic as well as photometric observation of the eclipsing sdB binary PTF1 J011339.09+225739.1 (PTF1 J0113) in a close (a = 0.722 ± 0.023 R_⊙), short period (P = 0.0933731(3)d) orbit. A quantitative spectral analysis of the sdB yields T_(eff.) = 29280 ± 720 K, log(g) = 5.77 ± 0.09 dex, and log(y) = −2.32 ± 0.12. The circular orbital velocity of the sdB of K_1 = 74.2 ± 1.7 km s^(−1) is derived from the radial velocity curve. Except for the strong reflection effect, no other light contribution of the companion could be detected. The light curves - recorded with ULTRACAM - were analyzed using the Wilson-Devinney code. We find an inclination angle of i = 79.88 ± 0.18°. Because our first attempts to determine q failed, we calculated large grids of synthetic lightcurves for several mass ratios. Because of degeneracy, good solutions for different mass ratios were found - the one at q = 0.24 is consistent with the sdB's canonical mass (M_(sdB) = 0.47 M_⊙). Accordingly, the mass of the companion is M2=0.112 ± 0.003 M_⊙. The radii of the two components were also derived: R_(sdB) = 0.178 ± 0.006 R_⊙ and R_2 = 0.158 ± 0.009 R_⊙. Thus, the results for the secondary are consistent with an M-dwarf as secondary

Additional Information

© 2018 Maximilian Wolz, published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. BY-NC-ND 4.0 Received: 2017-10-10. Accepted: 2017-12-08. Published Online: 2018-05-24.

Attached Files

Published - Spectroscopic_and_Photometric_Analysis_of_the_HW_Vir_Star_PTF1_J011339.09225739.1.pdf

Files

Spectroscopic_and_Photometric_Analysis_of_the_HW_Vir_Star_PTF1_J011339.09225739.1.pdf

Additional details

Created:
August 21, 2023
Modified:
October 18, 2023