Absolute parameters of the short-period binary HY Virginis from JHK light curves and spectroscopy

We present the first light curves in the infrared J, H and K filters of HY Vir. Based on HY Vir and template stars spectra in the region 8440–8870 Å, we classify as F0 both stellar components of the binary. Also, we obtain the first radial velocity curves of the system. The analysis of the JHK light curves is carried out using a code based in ATLAS model atmospheres and Roche geometry.From the spectroscopic and photometric data, absolute orbital and stellar parameters are derived that allow to classify HY Vir as a well detached binary with similar components. The comparison of the stellar components parameters with evolutionary models show that both components are well reproduced by an isochrone of age t ≃ 1.2 × 109 years, indicating that HY Vir is a relatively young binary.From published visual and our own infrared photometry we find not evidence of any significant infrared excess in the system. The estimated distance is d = 185 ± 15 pc, and we derive an interstellar reddening E(B − V) ≃ 0.04.