NOAO >   Observing Info >   Approved Programs >   2015A-0413

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Program Information for 2015A-0413


PI: Catherine A Pilachowski, Indiana U., catyp@astro.indiana.edu
Address: Astronomy Department, 727 E 3rd St, Bloomington, IN 47405 USA

CoI: Michael M Briley, Appalachian State U.
CoI: Jeffrey Gerber, Indiana U.
CoI: Eileen Friel, Indiana U.
CoI: Katherine L Rhode, Indiana U.
CoI: Enrico Vesperini, Indiana U.
CoI: Christian I Johnson, Harvard-Smithsonian Center for Astrophysics

Title: Developing a CN index using the 8100A CN Band

Abstract: We are investigating the use of the red CN system at 8100A to differentiate stellar populations in globular clusters. In addition to pODI observations, we wish to obtain spectra of the same systems that WINGS is observing with Hydra for the blue CN system to verify the utility of the red CN system spectroscopically. We will observe giants in M12, M71, and NGC 7006 at moderate resolution (3A) from 6500-8500A to measure the strength of the red CN system at 8100A. The red CN system has advantages over the blue CN system in that a) cool stars are brighter in the red, b) detectors and spectrographs are more efficient in the red, and c) seeing is better in the red. If the red CN index can be used and appropriately calibrated, then we can calibrate photometric and long-slit observations of globular clusters in Andromeda to identify and study multiple populations in globular clusters in that galaxy. pODI observations of M71, Pal 1, and NGC 2419 have already been obtained with the narrow-band 815 filter. Hydra observations will be used to calibrate those data as well. Spectroscopy of Pal 1 and NGC 2419 will be requested for 2015B.

Program Type: ITAC

Scheduled Nights:
Run 1 (2015A):  WIYN/HYDR -- 2n on Jun 05 - Jun 06 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 >   2015A-0413

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