NEAR-INFRARED OBSERVATIONS OF CIRCUMNUCLEAR STAR-FORMATION IN NGC-3351, NGC-3504, AND NGC-5248

High-resolution near-infrared (J and K band) images of the inner 50 '' of the hotspot galaxies NGC 3351, NGC 3504, and NGC 5248 were used to measure colors of star-forming regions. The hotspot colors are consis tent with ages of approximately 10(7) yr. Near-infrared (NIR) peaks in NGC 5248 are coincident with published HST UV peaks. In NGC 3351, NIR hotspots coincide with published H alpha peaks, which are offset from CO twin peaks. In addition, bright K-band emission exists without opt ical or gas peak counterparts, and reveals the underlying inner Lindbl ad resonance ring and older star formation sites. Published CO maps of NGC 3351 were used to determine that the Q stability parameter is les s than 1.4 in the ring, consistent with star formation. In NGC 3504, a ring of star formation is revealed in the (J-K) map at the location o f the inner inner Lindblad resonance, with a two-arm spiral originatin g outside of the ring. Circumnuclear star formation rates are 0.4 M. y r(-1) in NGC 3351 and 1.5 M. yr(-1) in NGC 5248; these rates may scale with galaxy Hubble type and total mass. We also observed the barred s pirals NGC 4123, 4303, 5350, and 5921. None of these show evidence of circumnuclear rings in the NIR. (C) 1997 American Astronomical Society .