Fundamental Parameters of the Eclipsing Binary DD CMa and Evidence for Mass Exchange

0549021 - ASÚ 2022 RIV US eng J - Journal Article
Rosales, J. A. - Mennickent, R.E. - Djurašević, G. - González, J. F. - Araya, I. - Cabezas, Mauricio - Schleicher, D.R.G. - Curé, M.
Fundamental Parameters of the Eclipsing Binary DD CMa and Evidence for Mass Exchange.
Astronomical Journal. Roč. 161, č. 4 (2021), č. článku 165. ISSN 0004-6256. E-ISSN 1538-3881
Institutional support: RVO:67985815
Keywords : close binary stars * eclipsing binary stars * stellar activity
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 5.491, year: 2021
Method of publishing: Limited access
https://doi.org/10.3847/1538-3881/abded0

We present a detailed photometric and spectroscopic analysis of DD CMa, based on published survey photometry and new spectroscopic data. We find an improved orbital period of P-o = 2.0084530(6) days. Our spectra reveal H beta and H alpha absorptions with weak emission shoulders, and we also find a color excess in the Wide-field Infrared Survey Explorer multiband photometry, interpreted as signatures of circumstellar matter. We model the V-band orbital light curve derived from the ASAS and ASAS-SN surveys, assuming a semidetached configuration and using the mass ratio and temperature of the hotter star derived from our spectroscopic analysis. Our model indicates that the system consists of a B2.5 dwarf and a B9 giant of radii 3.2 and 3.7 R, respectively, orbiting in a circular orbit of radius 6.75 R. We also found M-c = 1.7 0.1 M, T-c = 11,350 100 K, and M-h = 6.4 0.1 M, T-h = 20,000 500 K, for the cooler and hotter star, respectively. We find broad single emission peaks in H alpha and H beta after subtracting the synthetic stellar spectra. Our results are consistent with mass exchange between the stars and suggest the existence of a stream of gas being accreted onto the early B-type star.
Permanent Link: http://hdl.handle.net/11104/0325055