Absolute dimensions of the metallic-line eclipsing binary V501 Monocerotis

TL;DR

This study precisely measures the physical properties of the V501 Mon binary system, including masses, radii, and chemical compositions, and confirms the system's age and relativistic effects through detailed observations and analysis.

Contribution

The paper provides high-precision absolute dimensions and chemical abundances of V501 Mon, including the first detailed chemical analysis and a test of stellar evolution models with relativistic apsidal motion.

Findings

Masses and radii determined to better than 0.3% and 1.8%

Apsidal motion with 70% contribution from General Relativity

System age estimated at approximately 1.1 billion years

Abstract

We report extensive high-resolution spectroscopic observations and V-band differential photometry of the slightly eccentric 7.02-day detached eclipsing binary V501 Mon (A6m+F0), which we use to determine its absolute dimensions to high precision (0.3% for the masses and 1.8% for the radii, or better). The absolute masses, radii, and temperatures are M(A) = 1.6455 +/- 0.0043 M(Sun), R(A) = 1.888 +/- 0.029 R(Sun), and T(A) = 7510 +/- 100 K for the primary, and M(B) = 1.4588 +/- 0.0025 M(Sun), R(B) = 1.592 +/- 0.028 R(Sun), and T(B) = 7000 +/- 90 K for the secondary. Apsidal motion has been detected, to which General Relativity contributes approximately 70%. The primary star is found to be a metallic-line A star. A detailed chemical analysis of the disentangled spectra yields abundances for more than a dozen elements in each star. Based on the secondary, the system metallicity is near solar: [Fe/H] = +0.01 +/- 0.06. Lithium is detected in the secondary but not in the primary. A comparison with current stellar evolution models shows a good match to the measured properties at an age of about 1.1 Gyr.