THE LUMINOUS STARBURST GALAXY UGC-8387

We present broad-band J, H, and K images and K-band spectroscopy of the luminous starburst galaxy UGC 8387. The images show a disturbed morphology, tidal tails, and a single elongated nucleus. Near-infrared color maps constructed from the images reveal that the nuclear region is highly reddened. Strong emission from the central 3.''0 in the 2.166 mu m Brackett gamma, 2.122 mu m H-2 nu = 1-0 S(1), and 2.058 mu m He I lines is present in the K-band spectrum. From the Brackett gamma and published radio fluxes, we find an optical depth toward the nucleus of tau(V) similar to 24. The CO band heads produce strong absorption in the spectral region longward of 2.3 mu m. We measure a ''raw'' CO index of 0.17 +/- 0.02 mag, consistent with a population of K2 supergiants or K4 giants. The nuclear colors, however, are not consistent with an obscured population of evolved stars. Instead, the red colors are best explained by an obscured mixture of stellar and warm dust emission. The amount of dust emission predicted by the near-infrared colors exceeds that expected from comparisons to galactic H II regions. After correcting the spectrum of UGC 8387 for dust emission and extinction, we obtain a CO index of greater than or equal to 0.25 mag. This value suggests the stellar component of the 2.2 mu m light is dominated by young supergiants. The infrared excess, L(IR)/L(Ly alpha), derived for UGC 8387 is lower than that observed in galactic H II regions and M82. This implies that either the lower or upper mass cutoff of the initial mass function must be higher than those of local star-forming regions and M82. The intense nuclear starburst in this galaxy is presumably the result of merger activity, and we estimate the starburst age to be at least a few times 10(7) yr.