System Parameters for the Eclipsing B-Star Binary HD 42401

TL;DR

This study provides detailed orbital and stellar parameters for the eclipsing binary HD 42401, including masses, radii, and age, based on combined spectroscopic and photometric analysis, revealing the system's evolutionary status.

Contribution

First comprehensive orbital and physical parameter determination for HD 42401 using combined photometry and spectroscopy, highlighting its age and evolutionary state.

Findings

Orbital period of 2.18706 days with high precision.

Masses and radii of both stars precisely measured.

System age estimated to be over 25 million years.

Abstract

I present results from an optical spectroscopic investigation of the binary system HD 42401 (V1388 Ori; B2.5 IV-V + B3 V). A combined analysis of V-band photometry and radial velocities indicates that the system has an orbital period of 2.18706 +/- 0.00005 days and an inclination of 75.5 +/- 0.2 degrees. This solution yields masses and radii of M1 = 7.42 +/- 0.08 Solar Masses and R1 = 5.60 +/- 0.04 Solar Radii for the primary and M2 = 5.16 +/- 0.03 Solar Masses and R2 = 3.76 +/- 0.03 Solar Radii for the secondary. Based on the position of the two stars plotted on a theoretical H-R diagram, I find that the age of the system is > 25 Myr and that both stars appear overluminous for their masses compared to single star evolutionary tracks. A fit of the spectral energy distribution based on photometry from the literature yields a distance to HD 42401 of 832 +/- 89 parsecs.