# # Program information file # PROGRAM_ID 2023B027 PROGRAM_TITLE Measuring protostellar mass accretion rates using Brackett lines PROGRAM_INV1 Jonathan Williams PROGRAM_INV2 Leonardo Testi PROGRAM_INV3 Carlo Manara PROGRAM_INV4 Rik Claes PROGRAM_INV5 Antonella Natta PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG We propose to use SpeX to observe the Brackett alpha and gamma lines at R=1500 in a sample of pre-main sequence [Class II] and protostellar [Class I] sources in Ophiuchus. The observations of the Class II sample will allow usto calibrate the relationship between Br alpha luminosity and accretion luminosity. We will then apply this to determine the accretion rates in the younger, more embedded Class I sources to study this relatively poorly explored phase of high stellar growth. PROGRAM_ABSTRACT_END