[8] A jet was observed emanating from the nucleus and based on its movement the rotation period was calculated to be 15.31 ± 0.03 and 14.79 ± 0.02 hours.

[11] In 1699, it was observed by Gottfried Kirch[12] but was not recognized as a periodic comet until the discoveries by Tempel and Tuttle during the 1866 perihelion.

[15] Comet Tempel–Tuttle was recovered by J. Schubart in images taken by Michiel John Bester on 30 June 1965 using the 10-inch telescope of Boyden Observatory, South Africa.

[17] The comet was recovered on 4 March 1997 by Karen Meech, Olivier Hainaut and James "Gerbs" Bauer, at the University of Hawai`i.

[18] During the 1998 apparition the comet brightened more than predicted and reached an apparent magnitude of 7.4–7.8 in late February and could be observed with binoculars.

[5] This coincidence means that past streams from the comet at perihelion are still dense when they encounter Earth, resulting in the 33-year cycle of Leonid meteor storms.