NOAO >   Observing Info >   Approved Programs >   2015B-0609

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Program Information for 2015B-0609


PI: Donald Terndrup, Ohio State U., terndrup.1@osu.edu
Address:

CoI: Marc Pinsonneault, Ohio State U.
CoI: Jennifer A Johnson, Ohio State U.
CoI: Viraja Khatu, University of Western Ontario

Title: Metallicity Estimates for Halo GIants in the Kepler Field

Abstract: We have been working on a sample of halo giants in the Kepler field, with the goal of determining asteroseismic constraints on age and internal rotation/structure. A recent re-examination of the selection criteria has uncovered significantly more halo giants than had previously estimated, so the sample size has tripled to about 100. KOSMOS spectra in the blue (380 - 660 nm) can be used to obtain approximate temperatures and metallicities, which are critical for both for the asteroseismic analysis and for understanding the sample in a stellar population context. The targets are bright, with V = 13.0 to 16.0. Exposure times for S/N > 150 will be 5 to 10 minutes, so including time for acquisition we can observe 4-5 stars per hour. In 4 nights, therefore, we can get a large fraction of the sample of 100 stars, and this will include radial velocities to a precision of about 10-15 km/s. The latter part of the nights will be devoted to OSU service, calibration stars for the halo project, and for projects in support of Terndrup's NSF grant on stellar rotation. The density of targets on the sky is low, only a few per square degree, so observations will be conducted in longslit mode.

Program Type: Payback

Scheduled Nights:
Run 1 (2015B):  KP-4m/KOSMOS -- 4n on Sep 21 - Sep 24 2015


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 >   2015B-0609

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