  We revisit the atmospheric properties of the extremely hot Jupiter WASP-12b
in light of several new developments. First, new narrowband (2.315 micron)
secondary eclipse photometry that we present here, which exhibits a planet/star
flux ratio of 0.45% +/- 0.06 %, corresponding to a brightness temperature of
3640 K +/- 230 K; second, recent Spitzer/IRAC and Hubble/WFC3 observations; and
third, a recently observed star only 1" from WASP-12, which has diluted
previous observations and which we further characterize here. We correct past
WASP-12b eclipse measurements for the presence of this object, and we revisit
the interpretation of WASP-12b's dilution-corrected emission spectrum. The
resulting planetary emission spectrum is well-approximated by a blackbody, and
consequently our primary conclusion is that the planet's infrared photosphere
is nearly isothermal. Thus secondary eclipse spectroscopy is relatively
ill-suited to constrain WASP-12b's atmospheric abundances, and transmission
spectroscopy may be necessary to achieve this goal.
