Far infrared properties of late type dwarfs. Infrared fluxes of K and M dwarfs.

IRAS fluxes/upper limits are presented for a large sample of K and M dwarfs. Good agreement is found between the 12 micrometer fluxes and those derived from the photospheric models of Mould (1976). Relationships between the optical and infrared colors are derived. The active dMe/dKe stars appear systematically brighter in the infrared compared with the less active dM/dK stars, which could be attributed to more efficient nonradiative heating in their atmosphere. Any systematic differences found in our results when compared with those obtained from previous studies are attributed to the different analysis packages used.