Astron. Astrophys. 322, L13-L16 (1997)

Letter to the Editor

On the history of star formation in the bar of the Large Magellanic Cloud

A. Ardeberg ¹, B. Gustafsson ², P. Linde ¹ and P.-E. Nissen <sup>3

1</sup> Lund Observatory, Box 43, S-221 00 Lund, Sweden
² Astronomical Observatory, Uppsala University, Box 515, S-751 20 Uppsala, Sweden
³ Institute of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark

Received 20 February 1997 / Accepted 18 March 1997

Abstract

With the HST PC and uvby photometry, we investigate evolutionary signatures in a field in the centre of the LMC Bar. Field stars close to the turn off point in the HR diagram are used for a study of ages and evolution of the stellar populations dominating the Bar as well as for determination of the abundance of heavy elements. Including fainter stars, we derive the corresponding luminosity function. Here, we discuss some results obtained from a preliminary version of our data. The quality of our data is high. Two strong stellar populations are obvious. A young component contains approximately 30 % of the total number of stars. At least a considerable fraction of this component originated less than 500 Myears ago. The older population ranges in age between around 2 and 9 Gyears. The abundance of heavy elements is around [Me/H] = -0.6. The tentative luminosity function, down to y = 24, resembles in shape that predicted from earlier galactic and LMC data. Parallel to arrival of further HST data, our analysis continues.

Key words: Large Magellanic Cloud - stellar evolution - metallicity - luminosity function - uvby photometry

Send offprint requests to: A. Ardeberg, address as above

© European Southern Observatory (ESO) 1997

Online publication: June 5, 1998

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