  Near infrared imaging and spectroscopic observations of the extremely red
object (R-K~ 7 mag) CL 0939+4713 B have been obtained with the Near Infrared
Camera on the Keck I Telescope of the W. M. Keck Observatory. The imaging shows
a slightly elongated structure, while the spectroscopy shows a continuum break
that allows us to determine the redshift of z = 1.58 + 0.01/-0.03 for this
system. The fits of a range of models to the infrared spectrum suggests that it
is predominantly an old (> 10^9 yrs) stellar system that suffers little
extinction, while the measurerd R and I magnitudes suggests an age of ~ 3 x
10^8 years. The limit on the equivalent width of any emission line in the
infrared spectrum argues that CL 0939+4713 B is not an actively star forming
galaxy. This system, though similar in R-K color to HR 10 [also known as
J1645+46] (Dey et al. 1999), is much different in morphology and emission line
strengths, demonstrating the heterogeneity of extremely red extragalactic
objects (EROs) selected on the basis of large values of R-K.
