Abstract
LN Hya (BS 4912; HD 112374) has long been regarded as a post-AGB F-type supergiant, located at a high Galactic latitude (b = +36°.3). Earlier studies relied on limited spectroscopic and photometric material. We present a new data set comprising 73 medium-resolution (R ≈ 12,000) optical spectra obtained at the 0.81-meter telescope of the Three College Observatory (North Carolina, USA) in 2021—2025. We found regular variations in the radial velocities (RV) of absorption lines with a period of 148.63 ± 0.09 days. Our observations cover 10 most recent variability cycles and suggest that LN Hya is a binary system with an eccentric orbit (e = 0.19±0.02). In this paper, we describe the data reduction and analysis process as well as some spectral features of the system. Future plans for a deeper study of LN Hya that include analyzing existing photometric data and correlating them with the spectral variability are outlined.зорі над асимптотичною гілкою гігантів