NOAO >   Observing Info >   Approved Programs >   2016A-0136

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Program Information for 2016A-0136


PI: Livia Origlia, INAF - Bologna Observatory, livia.origlia@oabo.inaf.it
Address: INAF - Bologna Observatory, via Ranzani 1, 40127 BOLOGNA, ITALY ITALY

CoI: Francesco Ferraro, Universita di Bologna
CoI: Barbara Lanzoni, Universita di Bologna
CoI: Emanuele Dalessandro, Universita di Bologna
CoI: Alessio Mucciarelli, Universita di Bologna
CoI: Davide Massari, INAF - Bologna Observatory
CoI: Giuliana Fiorentino, INAF - Bologna Observatory

Title: MIRA STARS AS PROBES OF THE STAR FORMATION HISTORY OF THE COMPLEX STELLAR SYSTEM TERZAN 5

Abstract: We have discovered that Terzan 5 is a complex stellar system in the Galactic bulge, harboring stellar populations with very different iron content (Delta[Fe/H]~1 dex!) and possibly a few Gyrs different ages. Here we propose a spectroscopic study with Phoenix of the six Mira variables with known periods, to get accurate chemical abundances. This information, once combined with theoretical pulsation properties, can provide the first, direct evidence of an age spread in Ter5. Indeed, the short period Miras (P<300 days) may trace the oldest and metal-poor populations of Terzan 5, while the three Miras with long periods (P>300 days) may trace the younger, metal-rich one. Dating the epochs of the Terzan 5 star formation events has also a significant impact on our comprehension of the overall Galactic bulge formation.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2016A):  GEM-S-SVC/PHNX -- 6hrs band 3 (GS-2016A-Q-77)


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 >   2016A-0136

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