An Unusual Solar-Halo

Abstract

ON March 17, at Göttingen, a curious solar halo was observed by a friend and myself towards the time of sunset. The weather that day had been beautifully fine, but towards 5h. p.m. (Mean European Time) thin light clouds began to form, which covered the heavens with a thin white raiment. When the sun was about a few degrees from the horizon (the horizon at the place of observation was not the true one, for a large but not very distant hill intervenes towards the west), there seemed to be suddenly formed a halo of peculiar shape. Its form may be described as nearly, if not quite, parabolic, the axis of the parabola being vertical. Curiously enough, this parabolic form was not symmetrical with regard to the position of the sun, but the latter was situated some distance to the north of the axis. The above phenomenon was observed at about 5h.50m.—5h. 55m. p.m.