NOAO >   Observing Info >   Approved Programs >   2017B-0062

Small NOAO Logo

Program Information for 2017B-0062


PI: Ricardo Salinas, Gemini Observatory, rsalinas@gemini.edu
Address: South Operations Center, Colina el Pino s/n, La Serena, Coquimbo Chile

CoI: Kathy Vivas, CTIO
CoI: Jay Strader, Michigan State U.
CoI: Rodrigo Contreras, Pontificia Universidad Catolica de Chile
CoI: Catalina Labayru, Universidad de La Serena

Title: The role of stellar variability in the extended main sequence of intermediate-age LMC clusters

Abstract: The existence of multiple stellar populations is a widespread phenomenon in massive Galactic star clusters. In the LMC intermediate- age globular clusters, the presence of extended main sequence turn off points (MSTOs), has been either interpreted as evidence for multiple stellar populations or an effect of stellar rotation. Here we propose yet another ingredient to this puzzle: the fact that the MSTO of these clusters passes through the instability strip. Stellar variability at the MSTO level would artificially increase the magnitude and color spread if not properly taken into account, making it new alternative to explain this phenomenon. The proposed SOAR/SAM observations will be the first in-depth study of short-period variability in four LMC intermediate-age clusters, testing the variables-as-multiple-populations hypothesis and give new period-luminosity relations for these variables.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2017B):  SOAR/SAMI -- 3n on Jan 03 - Jan 05 2018


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 >   2017B-0062

noaoprop-help@noao.edu

Small NOAO Logo