  We present new 37.7 micron far-infrared imaging of the infrared luminous
(L_IR ~ 5.16x10^{11} L_sun) interacting galaxy Arp299 (= IC694 + NGC3690). We
show that the 38 micron flux, like the 60 and 100 micron emission, traces the
luminosity of star forming galaxies, but at considerably higher spatial
resolution. Our data establish that the major star formation activity of the
galaxy originates from a point source in its eastern component, IC694, which is
inconspicuous in the optical, becoming visible only at the near and
mid-infrared. We find that IC694 is two times more luminous than NGC3690,
contributing to more than 46% of the total energy output of the system at this
wavelength. The spectral energy distribution of the different components of the
system clearly shows that IC694, has 6 times the infrared luminosity of M82 and
it is the primary source responsible for the bolometric luminosity of Arp299.
