Then came what is the most suggestive feature in the whole event. On August 22 and 23 Dr. Wolf at Königstahl took with his then new Bruce objective some long exposure plates of the nova, and on them found, to his surprise, wisps of nebulous matter to the southeast of the star. On September 20 Ritchey, with a two-foot mirror of his own constructing exposed for four hours, brought the whole formation to light. It turned out to be a spiral nebula encircling and apparently emanating from the star. Its connection with the nova was patent. But there was more to come. Later plates taken at the Lick on November 7 disclosed the startling fact that the nebula was visibly expanding, uncoiling outward from the star. A plate by Ritchey on November 13 confirmed this, and still later plates by him in December, January, and February showed the motion to be progressive. At the same time the star showed no parallax, and the speed of the motion seemed thus to be indicated as enormous. Kapteyn suggested to account for it that appearance, not reality, was here concerned; that the nebula had always existed, and was only shown up by the light from the conflagration travelling outward from the nova at the rate of one hundred and eighty-six thousand miles a second. This would make the catastrophe to have occurred as far back as the time of James I, of which the news more truthful but less timely than that of the morning papers had only just reached us.
December 14, 1901.
January 7 and 9, 1902.
1902. February 8, 1902.
The Moving Nebula surrounding Nova Persei—after Ritchey.
But a little of that simple reasoning by which Zadig recovered the lost horses of the Sultan, and which from its unaccustomedness in the affairs of men got him suspected of having stolen them and very nearly caused his death, will show the untenableness of this idea and help us to a solution. In the first place we note that the star holds the very centre of the nebular stage, a remarkable prominence if the star has no creative right to the position. Then the same knots and patches of the nebulous configuration are visible in all the photographs, in the same relative positions, turned through corresponding angles as one will see for himself, all having moved symmetrically from one date to another. At the truly marvellous mimicry implied if different objects were concerned common sense instinctively shies, and very properly, as the chances against it are millions to one. Clearly it was not a mere matter of ethereal motion, but a very material motion of matter, which was here concerned. Something corpuscular emanating from the nova spread outward into space.