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 Te.=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 K1=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 (MsdB = 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: RsdB=0.178 ± 0.006 R⊙ and R2 = 0.158 ± 0.009 R⊙. Thus, the results for the secondary are consistent with an M-dwarf as secondary

Angaben zum Objekt

• Standort: Deutsche Nationalbibliothek Frankfurt am Main
• Umfang: Online-Ressource
• Sprache: Englisch

Verweise und Beziehungen

• Erschienen in: Spectroscopic and Photometric Analysis of the HW Vir Star PTF1 J011339.09+225739.1 ; volume:27 ; number:1 ; year:2018 ; pages:80-90 ; extent:11 ; Open astronomy ; 27, Heft 1 (2018), 80-90 (gesamt 11)

Beteiligte, Orts- und Zeitangaben

• Urheber: Wolz, Maximilian ; Kupfer, Thomas ; Drechsel, Horst ; Heber, Ulrich ; Irrgang, Andreas ; Hermes, J.J. ; Bloemen, Steven ; Levitan, David ; Dhillon, Vik ; Marsh, TomR.

Weitere Informationen

• DOI: 10.1515/astro-2018-0011
• URN: urn:nbn:de:101:1-2405281611483.618865492516
• Rechteinformation: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Letzte Aktualisierung: 14.08.2025, 10:48 MESZ