New orbital solution and detection of apsidal motion for the massive eclipsing binary HD 152590

JONATHAN ALEJANDRO MORENO; GABRIEL ANTONIO FERRERO

Lovaina

Congreso; 3,2,1: Massive Triples, Binaries and Mergers 2023; 2023

Katholieke Universiteit Leuven

Massive stars play a crucial role in the stars and planets' formation, as well as in the physical, chemical, and morphological structure of galaxies. However, several fundamental astrophysical parameters of high-mass stars remain poorly understood, with mass being the most important among them. The determination of absolute stellar masses is particularly important, as it provides a critical test for stellar evolution models. HD 152590 is an important system in this context, as until now, only two O7.5V stars had known masses. In this work, we present a new orbital solution for the massive eclipsing binary HD 152590, which allowed us to obtain the absolute mass of an O7.5V star (M1 = 20.01 ± 0.24 M⊙). To calculate the orbital solution, we obtained photometric data through differential photometry from a series of images in filters B, V, R, and I from the 0.6 m Helen Sawyer Hogg (HSH) telescope, which belongs to Complejo Astronómico El Leoncito (CASLEO) in Argentina. Combining this data with existing photometric and spectroscopic data from surveys such as OWN, ASAS, and TESS, we obtained a solution that provided the complete physical parameters of the system, including absolute masses, radii, separation, apparent magnitudes of the components, period, time of periastron passage, eccentricity, longitude of periastron, and inclination of the orbital plane. Finally, by comparing the orbital solutions for different epochs, we detected the presence of apsidal motion in the system and compare its rate with predictions from evolutionary models. Our findings highlight the importance of obtaining high-quality observational data for massive eclipsing binaries, which can provide crucial constraints on the physical properties and evolution of these fundamental astrophysical objects.