The search for infrared protostars.

A review of the search for infrared sources in star-forming regions, and studies of these sources and nearby interstellar matter, are presented. Particular attention is given to those objects at infrared wavelengths, and studies are directed toward the early evolution of massive-type stars. Star formation regions, globules and submillimeter sources, and infrared sources are discussed, and clustering and location of the infrared sources are considered. It is determined that the probable angular diameters of infrared sources in molecular clouds are less than or on the order of 10-10 to the 3rd AU, and that the most prominent absorption features are at 9.7 and 3.07 microns. In addition, infrared sources in molecular clouds are found to be among the most highly polarized of all astronomical objects. Finally, it is determined that OB stars generally form in groups at molecular cloud peaks and that they can reach large luminosities and begin ionizing radiation production, and, in the embedded stage and later, luminous stars undergo anisotropic mass loss.