Apsidal motion and physical parameters in the eclipsing system V490 Sct

TL;DR

This study provides detailed measurements of the physical parameters and apsidal motion of the eccentric eclipsing binary V490 Sct, highlighting the relativistic contribution to its orbital precession and confirming stellar models at 130 million years.

Contribution

First detailed physical and apsidal motion analysis of V490 Sct, including relativistic effects and comparison with stellar evolution models.

Findings

Masses and radii of both stars are precisely determined.

Apsidal motion rate is measured and compared with theoretical predictions.

Photometric parallax agrees with Gaia data.

Abstract

We report long-termed UBVRIRcIc photometry of the highly eccentric 12.04 day detached eclipsing binary V490 Sct (V =13.1, B9.5+A0, e = 0.40), which we use to determine its relative and absolute parameters. The absolute masses, radii, and temperatures are Ma = 2.33+/-0.1 Msun, Ra = 1.91+/-0.04 Rsun, and Ta = 9960+/-60 K for the primary and Mb = 2.24+/-0.1 Msun, Rb = 1.86+/-0.04 Rsun, and Tb = 9700+/-80 K for the secondary. The system displays a slow periastron advance that is dominated by general relativity (GR). Our measurement, dw/dt = 0.86 deg/century, is 32% less then the expected rate, dw/dt = 1.24 deg/century, which has an 83% contribution from GR. A comparison with current stellar evolution models shows a good match to the measured properties at an age of about 130 mln. years and Solar abundance. The photometrical parallax of the system pi = 0.77 +/- 0.02 mas, matches quite well the GAIA DR2 value, pi = 0.76 +/- 0.04 mas.