HUBBLE-SPACE-TELESCOPE ULTRAVIOLET IMAGING AND SPECTROSCOPY OF THE BRIGHT STARBURST IN THE WOLF-RAYET GALAXY NGC-4214

We have obtained an HST Faint Object Camera ultraviolet image and Fain t Object Spectrograph ultraviolet spectra of the central starburst reg ion in the nearby amorphous galaxy NGC 4214. The ultraviolet image rev eals a bright, compact, starburst knot surrounded by more than 200 fai nter pointlike sources. Spectral synthesis modeling of the ultraviolet spectrum of the central starburst knot suggests the stellar populatio n has an age of 4-5 Myr. The extinction-corrected ultraviolet flux imp lies that hundreds of O-type stars are contained within a diameter of at most 5 pc. The inferred number of Wolf-Rayet (W-R) stars implies th at the star formation episode occurred in a short duration burst. The starburst knot contains roughly twice the number of O stars as in a si milar size region centered on R136a in 30 Doradus, but it is slightly older. The knot in NGC 4214 is comparable in size and luminosity to th e starburst knots identified in the core of the W-R galaxy He 2-10 and to the super star clusters found in other star-forming galaxies. The number of Lyman continuum photons inferred from Ha measurements is at least a factor of 4 smaller than that predicted from the observed numb ers of hot stars; this starburst knot is thus ''density bounded'' to i onizing radiation. The fainter pointlike sources seen in the ultraviol et image are probably individual hot stars or small groups of stars. T he ultraviolet luminosity function of these objects is similar to that found for stars within 30 Doradus.