The Astronomical Journal, 141:126 (16pp), 2011 April doi:10.1088/0004-6256/141/4/126 C 2011. The American Astronomical Society. All rights reserved. Printed in the U.S.A. THE 100 Myr STAR FORMATION HISTORY OF NGC 5471 FROM CLUSTER AND RESOLVED STELLAR PHOTOMETRY Ruben´ Garc´ıa-Benito1,2, Enrique Perez´ 3, Angeles´ I. D´ıaz2,Jesus´ Ma´ız Apellaniz´ 3,4, and Miguel Cervino˜ 3 1 Kavli Institute of Astronomy and Astrophysics, Peking University, 100871 Beijing, China;
[email protected] 2 Departamento de F´ısica Teorica´ (C-XI), Facultad de Ciencias, Universidad Autonoma´ de Madrid, Ctra. Colmenar Viejo km 15.600, E-28049 Madrid, Spain;
[email protected] 3 Instituto de Astrof´ısica de Andaluc´ıa, CSIC, Aptdo. Correos 3004, E-18080 Granada, Spain;
[email protected], jmaiz@iaa,
[email protected] Received 2010 August 23; accepted 2011 February 1; published 2011 March 8 ABSTRACT We show that star formation in the giant H ii region NGC 5471 has been ongoing during the past 100 Myr. Using Hubble Space Telescope/Wide-Field Planetary Camera 2 F547M and F675W, ground-based JHKs , and GALEX FUV and NUV images, we have conducted a photometric study of the star formation history (SFH) in the massive giant extragalactic H ii region NGC 5471 in M101. We perform a photometric study of the color–magnitude diagram (CMD) of the resolved stars and an integrated analysis of the main individual star-forming clusters and of NGC 5471 as a whole. The integrated UV–optical–NIR photometry for the whole region provides two different reference ages, 8 Myr and 60 Myr, revealing a complex SFH, clearly confirmed by the CMD-resolved stellar photometry analysis.