The deepest hubble space telescope far-ultraviolet observations in the large magellanic cloud

We present a new analysis of the deepest pure-ultraviolet (UV) observations with the highest angular resolution ever performed. A set of 12 exposures with the Hubble Space Telescope (HST) WFPC2 and F160BW filter obtained in parallel observing mode, which cover ∼12 arcmin² in the Large Magellanic Cloud (LMC), north of the bar and in the 'general field' region of the LMC, contain stars with far-UV monochromatic magnitudes as faint as 22 mag. The 198 detected UV sources represent an accumulated exposure of ≥ 2 × 10⁴ s and reveal stars as faint as m_uv ≃ 20 mag. We combine these observations with deep UBVI charge-coupled device (CCD) imaging of the same region reaching as faint as V ≃ 26 mag, and reselect probable optical counterparts for the UV sources. After a two-stage search-and-analysis process, we detect robust counterparts for 129 stars. These are mostly upper main-sequence stars, from early B to early A spectral classes, with several F stars. We point out the lack of blue supergiants, which could have been easily detected in our survey. We measure a foreground extinction E(B - V) ≃ 0.08 mag by Galactic dust and a surface density of star formation rate twice the average Galactic value. These observations indicate that relatively recent star formation took place even off the bar of the LMC.