Ultraviolet and Optical Observations of HDE245770 / A:0535+26 System during an X-Ray Flare
Giovannelli, F.; Persi, P.; Bartolini, C.; Guarnieri, A.; Piccioni, A.; Ferrari-Toniolo, M.; Giangrande, A.
Italy
Abstract
We present high and low dispersion UV spectra of HDE 245770, which is the optical counterpart of the recurrent transient X-ray pulsar A 0535+26,during a decay of an X-ray flare. UBV photometric measurements and medium dispersion optical spectra were simultaneously obtained. The energy distribution of the star in the 12 10 micron range is compared with the models of Kurucz and Poeckert and Marlborough. In this phase, HDE 245770 does not show evaluable variations with respect to the quiescent X-ray phase.