A periodic comet, first seen in 1858 by the American astronomer Horace Parnell Tuttle (1837–1923) and rediscovered in 1907 by the French astronomer Michel Giacobini (1873–1938). No reliable orbit could be computed until a second rediscovery was made in 1951, by the Slovakian astronomer Lubor Kresák (1927–94). Observations finally yielded an orbit with a period of 5.5 years. At its 1973 return, the comet showed two surges of about 9 magnitudes in brightness, which remain unexplained and have not recurred. Its orbit has a perihelion of 1.05 au, aphelion 5.12 au, eccentricity 0.66, and inclination 9°.2 (which has reduced from nearly 19° when it was first discovered).

http://cometography.com/pcomets/041p.html Information page at Cometography website.