The OB association LH 58 in the Large Magellanic Cloud

We present charge coupled device (CCD) photometry and spectroscopy for stars in Lucke-Hodge 58, an isolated OB association in the Large Magellanic Cloud (LMC) northwest of 30 Doradus. The photometric catalog contains 839 stars with UBV magnitudes complete to V approximately = 19. We have obtained spectra and classified 35 stars; combined with previous published spectral types, we find 22 O-type stars. The earliest type is O3-4 V, and there are three Wolf-Rayet (WR) stars in the association. The slope of the initial mass function, Gamma = -1.7 +/- 0.3, is in good agreement with other LMC associations. The presence of several evolved supergiants with masses about 15-25 solar mass suggests that some star formation took place as early as 10 million years ago, but the majority of stars formed coevally within the past few million years.