Near Infra-Red Magnitudes of 248 Early-Type Emission-Line Stars and Related Objects

Abstract

SUMMARY Nearly 250 early-type emission-line stars have been observed in the near infra- red; approximately two thirds of these are found to exhibit excess radiation at these wavelengths. Two distinct mechanisms may contribute to the infra-red excesses: thermal radiation from circumstellar dust, and electron bremsstrahlung originating in a shell of ionized gas. It is not currently possible to distinguish between these two alternatives using infra-red photometry alone.