PI: Andrea Dupree, Harvard-Smithsonian Center for Astrophysics, email@example.com
Address: 60 GARDEN STREET, CAMBRIDGE, MA 02138 USA
CoI: Graeme H Smith, UC Santa Cruz
Title: Sleuthing Helium in NGC 2808
Abstract: The abundance of helium is believed to be a distinguishing characteristic of multiple evolutionary sequences in the color magnitude diagram of globular clusters, but its inferred abundance from the H-R diagram is highly model dependent. Using Gemini/PHOENIX spectra we detected helium in Omega Cen giants, wherein the presence of helium is associated with abundance patterns in light elements signaling high-temperature processing in a previous generation of stars. In a pilot program, we propose to measure the near-IR transition of He I with PHOENIX in red giants of NGC 2808 - a fiducial cluster exhibiting multiple episodes of star formation - to detect the presence and evaluate the abundance and evolution of this pivotal element.
Program Type: Standard/Galactic
Run 1 (2016B): GEM-S-SVC/PHNX -- 14.1hrs band 1 (GS-2016B-Q-8)
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360