IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2023B078 PROGRAM_TITLE Homogeneous stellar characterization for M dwarfs with confirmed giant planets PROGRAM_INV1 Tianjun Gan PROGRAM_INV2 Adam Burgasser PROGRAM_INV3 Christopher Theissen PROGRAM_INV4 Shude Mao PROGRAM_INV5 Sharon Wang PROGRAM_SCICAT extra-solar planets PROGRAM_ABSTRACT_BEG We propose to obtain SpeX spectra for 18 M-type stars with confirmed giant planets [72% of all such systems] identified by transit or radial velocity surveys. We will measure stellar metallicity, refine stellar radius and effective temperature as well as determine the stellar spectral type with the same methodology. With the homogeneously measured stellar iron abundance [Fe/H] and total metallicity [M/H], we will systematically study their preference of two populations: hot Jupiters and warm Jupiters around M dwarfs. We will compare our findings with results on FGK stars, and probe the formation channel of these extreme systems with the largest planet-to-star mass ratios. We will also compare our sample to a large set [>800 sources] of M stars also observed with SpeX with no giant planet detection. Our observations also allow us to refine planet properties like radius and equilibrium temperature. We will conduct our observations in the SpeX SXD mode with the 0.3'' x 15'' slit, which provides a resolution of R~2,000 over the wavelength range 0.7-2.55 microns. we choose to do auto IR guiding with the SpeX guider/slit viewer. We will collect at least four sets of AB-nodded sequences for each object in our target list. Due to the various brightness of our sample, we will vary the integration time per exposure from 11s to 180s as well as the number of cycles, but always require a sufficient total signal-to-noise ratio higher than 150 at 1.6 microns. We will also observe A0V standard stars for telluric calibration, and take SXD flat-field and arc-lamp exposures for instrument calibration. We will employ the Spextool, xtellcor and tellrv packages to reduce our spectra as well as the metal package to determine the stellar metallicity. PROGRAM_ABSTRACT_END