# # Program information file # PROGRAM_ID 2024A990 PROGRAM_TITLE Follow-Up Spectroscopy of Directly Imaged Low-Mass Companions to Young Stars in Taurus PROGRAM_INV1 Sam Walker PROGRAM_INV2 PROGRAM_INV3 PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG As part of our work to image young Taurus stars with the Keck 2 PyWFS, we have identified a bound companion to a young Taurus star that we believe to be planetary-mass from the color information we've already obtained. I am proposing to use SpeX in its Prism mode to obtain a spectrum of this object, which will be essential in determining the nature of this object. We will use this spectrum to compute the object's spectral type and determine the amount of dust extinction between us and this object, which is one of the major remaining sources of uncertainty in securely determining its mass. Sufficient signal-to-noise (>75) will also allow us to classify the object's surface gravity using spectral indices (Allers & Liu 2013), giving us a glimpse into the object's age and thus breaking the degeneracy inherent in making mass determinations of planetary-mass objects. This spectrum will also be invaluable in ensuring that the Gemini/GNIRS spectrum of this source we recently obtained is calibrated properly. PROGRAM_ABSTRACT_END