Page:The story of the comets.djvu/116

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
76
The Story of the Comets.
Chap.

After November 9 the comet gradually became fainter, and on November 16 Barnard found "nothing different in its appearance from the ordinary comet, except its size." It continued to grow fainter, and on January 4, 1893, "there was only the most excessively faint trace of the comet a feeble glow extremely difficult to see." Barnard then goes on to say:—

"Bad weather interfered with observations until January 16, when it cleared at dark. It seemed scarcely possible that the comet could be seen again, but from the importance of any positions of it, I thought it worth trying once more. The 12-inch was set for it, and upon looking in the telescope I was surprised to see a small, bright, hazy star. Thinking some mistake had been made, the telescope was again set only to find the same object. It seemed impossible that this star-like object could be the excessively faint and diffused nebulosity previously seen. Observations for motion, however, soon showed that it was in reality the comet. . . . In the finder, however, it appeared perfectly stellar and could not possibly be distinguished from an 8th magnitude star. At 9h 50m the mean of two measures gave 32".4 for the diameter. At this time there had begun to appear in the condensation a small nucleus which had not been visible at first. It seemed to brighten rapidly while being watched, and soon became very distinct. At 10h 20m there was no question but that the nucleus was brightening; it seemed to form and become clear and distinct right before one's eyes.

At 10h 30m the 36-inch was turned upon the comet. It appeared very beautiful and remarkable in the great telescope. With this instrument its diameter was measured = 44". In the great telescope it looked exactly as it did on November 8 when first seen with the 12-inch. It was pretty well terminated and had a pretty bright nucleus. A few minutes later another set of measures was made of its diameter = 47".

The nebulosity was bluish, but the nucleus was hazy and yellowish and central. At 10h 55m there was a feeble glow about the comet, something like 1' in diameter. Further measures were made with the great telescope: at 11h 13m diameter = 47".3. On this night there was no question whatever but that the nucleus actually formed in a few hours' time, while the comet was under observation; at the same time the body of the comet appeared to be expanding gradually."

During the next following nights the comet was watched gradually growing in size, and on—

"January 20, with the 36-inch at 6h 45m the measured diameter was 136". The nucleus was of the 10th magnitude and quite conspicuous, while the comet was much brighter in the middle. Taken altogether the object looked like a spherical mass of vapour, rounding up beautifully, with the nucleus shining in the middle.

January 22. With the 36-inch the comet was very diffused and was estimated to be 3' or 3'.5 in diameter. At 7h 30m the nucleus was very indistinct and about 12th magnitude. There was a hazy glow close about the nucleus that seemed to partially hide it.