RADIO-CONTINUUM OBSERVATIONS OF A SMALL SAMPLE OF HOT STARS

Radio-continuum observations (mostly at 6 cm) of 15 stars with spectral types between O6 and A5 are presented. These data were obtained as part of several Very Large Array* programs. Ten of the observed stars were not detected as sources and have typical 3σ upper limits ∼0.2 mJy. The stars that were detected as radio sources include three O stars (σ Ori AB, S Mon, and HR 8281), a Be star (γ Cas), and (possibly) a B dwarf star (HD 26676). Evidence that the radio emission from σ Ori AB and S Mon is probably nonthermal in nature, and weaker evidence that the HR 8281 radio source is also possibly nonthermal, is presented. The radio observations of all the detected stars, and also of several of the undetected stars for which previous detections have been claimed, are discussed in detail.