Astronomical Topics

Abstract

Encke's Comet.—Telegrams from Profs. Shapley and Strömgren report the detection of this comet by Mr. Bobone at Cordoba (Argentine), on June 21, at 22h.23.2m.U.T.in R.A. 7h.35m. 24s., N.Decl.8° 22′. The R.A. is 56 s. less and the Decl. 44′ less than the values predicted by Matkiewicz; this implies that the time of perihelion is about 18 hours earlier than the predicted value, which was June 3.85 U.T. For most comets this would not be regarded as an unreasonable amount, but this comet has been so carefully studied ever since 1819 that the predictions are usually accurate to an hour. It is too large to be due to Mercury, though a little of it may be due to that planet, if Matkiewicz did not allow for its effect; it was not very far from the comet at the last perihelion passage. Possibly the accelerative effect, which was noted in the last century, but which had nearly died out, has revived again. This is the first detection of a comet for ten months; the cometary nature of the object reported by Prof. Nakamura last November is doubtful.