INFRARED PHOTOMETRY OF RR TELESCOPII AND OTHER EMISSION-LINE OBJECTS

Infra-red measurements at three or more wavelengths between 1-25 and 20 microns are presented for 16 emission-line objects in the later stages of their evolution. In the slow nova RR Tel, the infra-red energy distribution resembles that from free-free and free-bound processes, but is two orders of magnitude stronger than expected from the visible spectrum. A cool stellar component is detected for the first time in three objects and confirmed in eight known symbiotic stars. Radiation from dust is found to be characteristic of a small subclass of symbiotic stars and of two unusual planetary nebulae. © 1973 Royal Astronomical Society.