Socket stars: Ubvrijk radial profiles
Visual inspection of stars embedded in H II nebulae has shown a significant fraction to be surrounded by nearly symmetric extended regions within which the nebular brightness is apparently significantly fainter than is typical for the surrounding area. These "socket stars" might be caused by a bubble in the nebula blown out by a stellar wind or they might be caused by a circumstellar envelope of dust hiding the emission behind the star. As such, the sockets could be the first manifestation of a previously unknown component of pre-main-sequence stars. Unfortunately, no quantitative proof of the existence of sockets has been presented. To fill this need, I have imaged 10 socket stars and six background stars with CCD cameras and infrared array cameras. From these images, I have constructed radial plots which should reveal dips in brightness immediately outside the seeing disk. The radial plots do not show any evidence for the existence of sockets. A detailed examination of the photographs originally used to identify the sockets shows that the causes of these reports are (1) artifacts resulting from the photographic process of dodging and (2) random coincidence of stars with local minima in nebular brightness. Thus, I conclude that "socket stars" do not exist.
Publication Source (Journal or Book title)
Schaefer, B. (1995). Socket stars: Ubvrijk radial profiles. Astrophysical Journal, 444 (2), 739-747. https://doi.org/10.1086/175646