Discovery
The 1908 January 7 issue of the Astronomische Nachrichten contained the announcement that M. F. J. C. Wolf (Königstuhl Observatory, Heidelberg, Germany) had recovered periodic comet Encke on a photographic plate exposed on 1908 January 2.74. He said the ephemeris required a correction of +2.4m in right ascension and -24' in declination. Wolf also noted that a further inspection of a photographic plate exposed on 1907 December 25.78 revealed the "comet" near the edge of the plate. He estimated the magnitude as 13 on both dates.
Positions
Analysis
In the 1908 January 21 issue of the Astronomische Nachrichten, Wolf provided further measurements of this object's position for January 13, 14, 15, 18, and 19. He gave the magnitude as 12.0 for the first three dates and 12.5 for the last two. Interestingly, the editor of this journal, H. Kobold, pointed out in this same issue that the positions did not run parallel to the predicted ephemeris for periodic comet Encke. His numbers indicated the object was moving at a different speed.
The 1909 February issue of the Monthly Notices of the Royal Astronomical Society mentions that the object found by Wolf "has probably no connection with [comet Encke]. The January observations displayed such deviations from the computed path, and such discrepancies among themselves, that Professor Backlund doubted the identity of the two objects...." Backlund even went so far as to recalculate the planetary perturbations since the last apparition of comet Encke, but found no errors. He did suggest that the object found by Wolf could be a fragment of comet Encke "and that, by the process of division, one of the parts had been turned into an orbit sensibly different from the original."
The same issue of the Monthly Notices noted the investigations of two other astronomers. C. W. L. M. Ebell took positions from January 2, 13, and 19, and calculated a parabolic orbit that bore no resemblance to the orbit of comet Encke and had a rather large perihelion distance. E. Weiss suggested the positions obtained on December 25 and January 2 belonged to a different object than those positions from the period of January 13 to 19. Unfortunately, he found that a wide variety of orbits could fit these positions when different distances were assumed. Even though Weiss came to the conclusion that the object could reappear in Northern Hemisphere skies during May of 1908, no further observations were obtained.
The solution to the problem of whether or not Wolf's object was associated with comet Encke was finally resolved in the 1919 June 6 issue of the Astronomische Nachrichten. F. K. Zweck found that the positions very closely represented those expected for minor planet 516 Amherstia on the dates given.
Sources:
Astronomische Nachrichten, 177 (1908 Jan. 7), p. 31
Astronomische Nachrichten, 177 (1908 Jan. 21), p. 79
Popular Astronomy, 16 (1908 Feb.), p. 113
Monthly Notices of the Royal Astronomical Society, 69 (1909 Feb.), pp. 295-7
Nature, 81 (1909 Jul. 15), p. 83
Astronomische Nachrichten, 208 (1919 Jun. 6), p. 345
Monthly Notices of the Royal Astronomical Society, 80 (1920 Feb.), p. 408
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