IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2022B076 PROGRAM_TITLE Star Spots on the Planet-hosting Star HD189733 PROGRAM_INV1 Drake Deming PROGRAM_INV2 Guangwei Fu PROGRAM_INV3 Thomas Greene PROGRAM_INV4 Gregory Henry PROGRAM_INV5 Jegug Ih PROGRAM_SCICAT extra-solar planets PROGRAM_ABSTRACT_BEG The active star HD189733 hosts a giant transiting planet that is very favorable for atmospheric characterization. The planet is the target of four Cycle-1 programs on JWST. However, spots on this active star can bias the results of the JWST observations. We propose to measure the size and temperature of the star spots, facilitating more accurate interpretation of the JWST data. We will observe the star using high resolution iSHELL spectroscopy in the K-band. A cross-correlation method applied to the difference in the stellar spectrum on two nights will detect the star spots via their changing radial velocity from stellar rotation. The cross-correlation function is sensitive to both the size and temperature of the star spots, and we will break that degeneracy using visible light photometry from TESS and ground-based facilities. PROGRAM_ABSTRACT_END