Further detections of OH masers in carbon stars with silicate features

A sample of J-type carbon stars was searched for OH maser emission. The new detection of three OH lines towards two silicate carbon stars is reported. In V778 Cyg, previously known as the main-lines (1665 and 1667 MHz) maser source, the satellite 1612 MHz emission was discovered while in NSV 2814 the main OH lines were detected. The presence of OH maser lines confirms the former suggestion that oxygen-rich material is located in the vicinity ($\approx$ $10^{15-16}$ cm) of silicate carbon stars.Comment: LaTeX2e, 4 pages with 2 figure