Survey observations of emission-line stars in the Orion region. II. The KISO area A-0903.

Survey observations of H-alpha emission stars have been carried out with the Kiso Schmidt telescope for the Kiso sky area A-0903 (5 x 5 deg, centered at alpha = 5h 20m and delta = 0 deg 0 min). 254 H-alpha emission objects and three suspected stars have been detected. Among the detected objects, 247 are new emission-line stars and one is a nonstellar object. The celestial coordinates (alpha, delta) and the V magnitudes were measured along with an eye estimation of the H-alpha intensities. It was found that the emission-line stars are distributed rather uniformly over area A-0903 with a magnitude range of V = 13-17. This brightness distribution suggests that most of the detected emission-line stars are of T Tauri type. The surface distributions of the emission-line stars and of the members of Ori OB1a and 1b are discussed with particular attention given to the formation sites of high- and low-mass stars.