A phase change in X Persei

1991

We present a series of optical spectroscopic and infrared photometric observations of the Be/X-ray binary system X Per made over the last four years. Over this period the Hα line profile changed from emission to absorption, accompanied by a decrease in the infrared flux by over a magnitude and a flattening of the infrared spectrum. Such behaviour is consistent with the loss of the circumstellar disc or shell of material around the Be star and the reversion to a normal O/B-type star.