PI: Constantine Deliyannis, Indiana U., email@example.com
Address: Astronomy Department
CoI: Qinghui Sun, Indiana U.
CoI: Bruce A Twarog, U. of Kansas
CoI: Barbara Anthony-Twarog, U. of Kansas
CoI: Aaron Steinhauer, State University of New York Geneseo
CoI: Dianne Harmer, NOAO
Title: Stellar Physics via Li in NGC 2420, M67, and M48
Abstract: We propose to continue our WIYN/Hydra survey of open cluster A(Li) (using the Li I line at 6708 ) as a probe of physical mechanisms occurring inside stars. These studies are not only fundamental for stellar interiors, but also address the (arguably) even more fundamental question of how normal (or abnormal) our Sun might be. This past winter we completed data acquisition on evolved stars in the metal-poor OC NGC 2506, and on the giants of the very old OC NGC 188. During 2018A we propose to: a) complete data acquisition of solar-mass dwarfs in NGC 188; b) begin (and with good weather complete) a survey of evolved stars in the metal-poor OC NGC 2420, which forms a crucial comparison to NGC 2506; c) if time permits, begin a survey of solar-twins in the solar- aged OC M67; our 1-degree UBVRI analysis of newly identified members outside the central half-degree provides vital info for selecting the best solar-twins and for the subsequent precision analysis of the spectra; and d) if time permits, begin a survey of dwarfs in the very rich, low-reddening, nearby, 300-Myr-old OC M48, for which we are also now completing analysis of UBVRI data in a 1-degree field. This will be by far the richest OC dwarf sample studied and as such is expected to yield insights on all aspects of dwarf Li depletion (the formation of the hot side, center, and cool side of the Li dip; the halo-like Li plateau; and G dwarf Li depletion, to list a few). It is highly probably that at least some of these projects will comprise Qinghui's PhD thesis. We expect to collect many of these data during 2017B. However, given the pattern of poor weather during the past several winters, we expect that at least some, and possibly even most, of the proposed data will not be acquired; we thus propose to continue during February, 2018. If the above goals should be completed, we will continue along similar lines with (for example) M41 (for which we are analyzing photometry, to compare to M48), and more configurations in NGC 188 (to build up statistics, which has proven invaluable in our recent work with other clusters).
Program Type: ITAC
Run 1 (2018A): WIYN/HYDR -- 5n on Mar 11 - Mar 12 2018, Apr 07 - Apr 09 2018
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360