2024/10/28 by Yasir Abdul Qadir, A. Berdyugin, Qadir, Yasir Abdul +9
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations
paper · pdf · doi:10.48550/arxiv.2410.20991
This study continues our investigation of early-type binaries using high-precision broad-band polarimetry, focusing on HD 165052, a massive O+O-type binary in the young cluster NGC 6530. Our aim was to monitor linear polarization variations and independently determine the orbital period through polarization data analysis. By examining the phase-locked Stokes parameters, we estimated the orbital inclination at about 55+5/-55 deg, and the orientation at 148+20/-22 deg. The binary's rotation direction is clockwise. Using the Dipol-2 polarimeter with the 60 cm KVA and Tohoku T60 telescopes, we achieved polarization measurement accuracy around 0.01 percent in the B, V, and R passbands. Period analysis identified a strong periodic signal with a cycle of about 1.48 days, corresponding to half of the orbital period of about 2.96 days. The second Fourier harmonics suggest a symmetric scattering geometry, likely due to electron scattering in interacting stellar winds. Our estimates indicate a mass-loss rate of approximately 3.5 x 10^(-7) solar masses per year. Observations of neighboring stars in NGC 6530 revealed complex interstellar polarization behaviors within the cluster, enhancing our understanding of its polarimetric environment.