  Herschel PACS and SPIRE images have been obtained over a 30'x30' area around
the well-known carbon star CW Leo (IRC +10 216). An extended structure is found
in an incomplete arc of ~22' diameter, which is cospatial with the termination
shock due to interaction with the interstellar medium (ISM) as defined by Sahai
& Chronopoulos from ultraviolet GALEX images. Fluxes are derived in the 70,
160, 250, 350, and 550 um bands in the region where the interaction with the
ISM takes place, and this can be fitted with a modified black body with a
temperature of 25+-3 K. Using the published proper motion and radial velocity
for the star, we derive a heliocentric space motion of 25.1 km/s. Using the
PACS and SPIRE data and the analytical formula of the bow shock structure, we
infer a de-projected standoff distance of the bow shock of R0 =
(8.0+-0.3)x10^17 cm. We also derive a relative velocity of the star with
respect to the ISM of (106.6+-8.7)/sqrt(n_ISM) km/s, where n_ISM is the number
density of the local ISM.
