NOAO >   Observing Info >   Approved Programs >   2019A-0334

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Program Information for 2019A-0334


PI: Verne V Smith, NOAO, vsmith@noao.edu
Address: CSDC, 950 N. Cherry Ave., Tucson, AZ 85719 USA

CoI: Katia Cunha, U. of Arizona
CoI: Cintia F Martinez, Observatorio Nacional Brazil
CoI: Johanna Teske, Carnegie Institution of Washington
CoI: Steve B Howell, NASA Ames Research Center
CoI: Simon C Schuler, University of Tampa
CoI: Luan Ghezzi, Observatorio Nacional Brazil
CoI: Jayadev Rajagopal, NOAO

Title: Accurate Stellar Characterization for Kepler and Kepler Extended Mission (K2) Exoplanet Host Stars and Prototyping TESS Follow-up

Abstract: The determination of accurate physical parameters for stars that host exoplanets is a crucial step in characterizing the size and nature of the planets themselves. In addition to the basic stellar parameters of effective temperature (T$_{rm eff}$), surface gravity (most often characterized by log g), stellar mass, and stellar radius, the stellar chemical composition is important in understanding any connections between planetary formation and stellar chemistry. The chemical composition of the star reflects the chemistry of the interstellar cloud from which the star and its planets formed, while the abundances of key metals, such as Fe, Mg, or Si, or the ratio of C/O may affect the nature of the planetary system architecture. High-resolution spectroscopy is an excellent tool with which to both derive accurate stellar physical parameters, along with detailed chemical abundances. This proposal targets exoplanet host-stars discovered by both the original Kepler Mission and the Kepler Extended Mission (K2) surveys and subject them to accurate stellar parameter determinations and detailed chemical abundance analyses. The 2$^{nd}$ Data Release (DR2) from the Gaia mission in April 2018 (since the last proposal cycle) has improved stellar characterization tremendously. Gaia parallaxes have now provided rather accurate distances to a significant fraction of Kepler and K2 exoplanetary host stars. With accurate distances, the FGK main- sequence host-star luminosities can be determined and stellar radii calculated from R$^{2}$= L/(4$pi$$sigma$T$_{rm eff}$$^{4}$). We have shown that accurate effective temperatures can be derived from the high- resolution spectra obtained here, where typical uncertainties are $Delta$T$_{rm eff}$$sim$$pm$40K (much less than 1% uncertainty for FGK dwarfs). The combination of quantitative, high-resolution spectroscopic analyses with Gaia parallaxes is yielding the most accurate determinations of stellar radii, and hence exoplanetary radii, to-date for large numbers of systems. The results obtained by our team will both strengthen constraints on the nature of the planets, as well as the formation and evolutionary history of the exoplanetary systems. This has been an ongoing program and part of this project forms part of an ongoing Ph.D. thesis.

Program Type: Standard/NASA WIYN

Scheduled Nights:
Run 1 (2019A):  WIYN/HYDR -- 3.5n on Mar 15 - Mar 18 2019
Run 2 (2019A):  WIYN/HYDR -- 9n on May 11 - May 13 2019, May 15 - May 16 2019, May 19 - May 22 2019


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2019A-0334

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