  We have spectroscopically discovered a pair of twin, nitrogen-type,
hydrogen-rich, Wolf-Rayet stars (WN8-9h) that are both surrounded by circular,
mid-infrared-bright nebulae detected with the Spitzer Space Telescope and MIPS
instrument. The emission is probably dominated by a thermal continuum from cool
dust, but also may contain contributions from atomic line emission. There is no
counterpart at shorter Spitzer/IRAC wavelengths, indicating a lack of emission
from warm dust. The two nebulae are probably wind-swept stellar ejecta released
by the central stars during a prior evolutionary phase. The nebulae partially
overlap on the sky and we speculate on the possibility that they are in the
early stage of a collision. Two other evolved massive stars have also been
identified within the area subtended by the nebulae, including a carbon-type
Wolf-Rayet star (WC8) and an O7-8 III-I star, the latter of which appears to be
embedded in one of the larger WN8-9h nebulae. The derived distances to these
stars imply that they are coeval members of an association lying 4.9 (1.2) kpc
from Earth, near the intersection of the Galaxy's Long Bar and the
Scutum-Centaurus spiral arm. This new association represents an unprecedented
display of complex interactions between multiple stellar winds, outflows, and
the radiation fields of evolved massive stars.
