# # Program information file # PROGRAM_ID 2023B067 PROGRAM_TITLE Spectroscopic monitoring of young stars with variable warm dust PROGRAM_INV1 Lei Chen PROGRAM_INV2 Attila Moor PROGRAM_INV3 Agnes Kospal PROGRAM_INV4 Peter Abraham PROGRAM_INV5 Foteini Lykou PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG Studies of dust evolution in the inner region of Herbig star HD 169142 suggest formation and evolution of second-generation dust. In order to study whether similar processes also happen in other young stars, we propose spectroscopic monitoring of four young stars with variable warm dust, using IRTF/SpeX, in order to study the nature of the dust components and the mechanism of variability. While previous photometric monitoring suggest yearly variability, our SpeX monitoring will study varibility on monthly scale. With the spectral coverage, we can study the dust temperature distribution and its temporal variation. We will study the temporal changes in accretion rate, using the emission line as accretion tracer. The program is a continuation of our ongoing 2023A program. PROGRAM_ABSTRACT_END