Calibration of stellar and atmospheric models using the Hyades

Abstract

Calibration and benchmarking of evolutionary and atmospheric models is essential for the study of low-mass stars and brown dwarfs, as for isolated objects these models are the only way to determine basic parameters like mass and age. The Hyades star cluster with an age of around 625 Myr and located at the distance of ~ 45 pc, is the most accessible cluster in the solar neighborhood. R\"oser et al. (2011) establish a list of 724 likely Hyades members. Using available literature data (HST, HIPPARCOS, WDS, Patience et al. 1998, Mermilliod et al. 2009, Morzinski 2011) and our own lucky imaging observations with AstraLux at the 2.2m telescope in Calar Alto, we establish a single-star sequence containing 255 Hyades members spanning the mass range ~ 0.2--1.5 solar masses . This sequence is used for testing and calibration of various existing stellar and atmospheric models (PADOVA, DARTMOUTH, BCAH, BT-Settl)