Fundamental parameters of the massive eclipsing binary HM1 8

BENVENUTO, O G; BARBÁ, R H; FERRERO, G A; MORRELL, N I; MASSEY, P; RODRÍGUEZ, C N; GAMEN, R; ARIAS, J

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021 vol. 508 p. 2179 - 2193

0035-8711

We present a comprehensive study of the massive binary system HM1~8, based on multi-epoch high resolution spectroscopy, $V$-band photometry and archival X-ray data.Spectra from the {it OWN Survey}, a high resolution optical monitoring of Southern O and WN stars, are used to analyse the spectral morphology and perform quantitative spectroscopic analysis of both stellar components. The primary and secondary components are classified as O4.5~IV(f) and O9.7~V, respectively. From a radial-velocity (RV) study we derived a set of orbital parameters for the system.We found an eccentric orbit ($e=0.14 pm 0.01$) with a period of $P = 5.87820 pm 0.00008$~days. Through the simultaneous analysis of the RVs and the $V$-band light curve we derived an orbital inclination of $70.0^{circ} pm 2.0$ and stellar masses of $M_a=33.6^{+1.4}_{-1.2}~ext{M}_{sun}$ for the primary, and $M_b=17.7^{+0.5}_{-0.7}~ext{M}_{sun}$ for the secondary. The components show projected rotational velocities $v_1sin{i}=105 pm 14~ext{km~s}^{-1}$ and $v_2sin{i}=82 pm 15~ext{km~s}^{-1}$, respectively. A tidal evolution analysis is also performed and found to be in agreement with the orbital characteristics. Finally, the available X-ray observations show no evidence of a colliding winds region, therefore the X-ray emission is attributed to stellar winds.