An Infrared Emission‐Line Galaxy atz= 2.43

An object discovered during an infrared survey of the field near the quasarB2 0149+33 has an emission line at 2.25$\mu$m that we interpret as H$\alpha$ ata redshift of 2.43. The K-band image shows two compact components 10 kpc apartsurrounded by more extended emission over ~20 kpc. The H$\alpha$ emissionappears to be extended over ~15 kpc (2") in a coarsely sampled (0".8/pixel)image. The star formation rate may be as high as 250 - 1000 M$_\odot$yr$^{-1}$, depending on the extinction. Alternatively, the line may be poweredby an active nucleus, although the probability of serendipitously discoveringan AGN in the survey volume is only ~0.02. The increasing number of similarobjects reported in the literature indicate that they may be an important,unstudied population in the high redshift universe.