NOAO >   Observing Info >   Approved Programs >   2016B-0187

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Program Information for 2016B-0187


PI: Andrea Dupree, Harvard-Smithsonian Center for Astrophysics, adupree@cfa.harvard.edu
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

Scheduled Nights:
Run 1 (2016B):  GEM-S-SVC/PHNX -- 14.1hrs band 1 (GS-2016B-Q-8)


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NOAO >   Observing Info >   Approved Programs >   2016B-0187

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