  The gravitationally lensed star WHL0137-LS, nicknamed Earendel, was
identified with a photometric redshift $z_{phot} = 6.2 \pm 0.1$ based on images
taken with the Hubble Space Telescope. Here we present James Webb Space
Telescope (JWST) Near Infrared Camera (NIRCam) images of Earendel in 8 filters
spanning 0.8--5.0$\mu$m. In these higher resolution images, Earendel remains a
single unresolved point source on the lensing critical curve, increasing the
lower limit on the lensing magnification to $\mu > 4000$ and restricting the
source plane radius further to $r < 0.02$ pc, or $\sim 4000$ AU. These new
observations strengthen the conclusion that Earendel is best explained by an
individual star or multiple star system, and support the previous photometric
redshift estimate. Fitting grids of stellar spectra to our photometry yields a
stellar temperature of $T_{\mathrm{eff}} \simeq 13000$--16000 K assuming the
light is dominated by a single star. The delensed bolometric luminosity in this
case ranges from $\log(L) = 5.8$--6.6 $L_{\odot}$, which is in the range where
one expects luminous blue variable stars. Follow-up observations, including
JWST NIRSpec scheduled for late 2022, are needed to further unravel the nature
of this object, which presents a unique opportunity to study massive stars in
the first billion years of the universe.
