HST OBSERVATIONS OF THE FIELD STAR POPULATION IN THE LARGE-MAGELLANIC-CLOUD

We present V and I photometry, obtained with the Hubble Space Telescop e, for similar to 15 800 stars in a field in the inner disc of the Lar ge Magellanic Cloud. We confirm previous results indicating that an in tense star formation event, probably corresponding to the formation of the LMC disc, occurred a few times 10(9) yr ago. We find a small but real difference between our field and one further out in the disc obse rved by Gallagher et al.: either star formation in the inner disc comm enced slightly earlier, or the stars are slightly more metal-rich. We also find evidence for a later burst, around 1 Gyr ago, which may corr espond to the formation of the LMC bar. About 5 per cent of the stars in our field are substantially older than either burst, and are probab ly members of an old disc or halo population with age similar to 12 Gy r.