  We report the detection of carbon monoxide (CO) and dust, formed under
hostile conditions, in recurrent nova V745 Sco about 8.7 days after its 2014
outburst. The formation of molecules or dust has not been recorded previously
in the ejecta of a recurrent nova. The mass and temperature of the CO and dust
are estimated to be T(CO) = 2250 +/- 250 K, M(CO) = (1 to 5) E-8 solar masses,
and T(dust) = 1000 +/- 50 K, M(dust) approximately E-8 to E-9 solar masses
respectively. At the time of their detection, the shocked gas was at a high
temperature of approximately E+7 K as evidenced by the presence of coronal
lines. The ejecta were simultaneously irradiated by a large flux of soft X-ray
radiation from the central white dwarf. Molecules and dust are not expected to
form and survive in such harsh conditions; they are like snowflakes in a
furnace. However, it has been posited in other studies that, as the nova ejecta
plow through the red giant's wind, a region exists between the forward and
reverse shocks that is cool, dense and clumpy where the dust and CO could
likely form. We speculate that this site may also be a region of particle
acceleration, thereby contributing to the generation of gamma-rays.

Solar and Stellar Astrophysics