| Discovery | |
|---|---|
| Discovered by: | Arno Arthur Wachmann |
| Discovery date: | May 2, 1930 |
| Alternate designations: | 1930 VI; 1979 VIII; 1990 VIII; 1994w |
| Orbital characteristics A | |
| Epoch: | 2011-Feb-08 (JD 2455600.5) |
| Aphelion: | 5.184 AU |
| Perihelion: | 0.9426 AU |
| Semi-major axis: | 3.063 AU |
| Eccentricity: | 0.6923 |
| Orbital period: | 5.36 yr |
| Inclination: | 11.379° |
| Last perihelion: | June 6, 2006[1] |
| Next perihelion: | October 16, 2011[1][2] |
73P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 3, is a periodic comet in our solar system which is in the process of disintegrating. Starting the 2011 perihelion passage the primary component 73P-C was recovered on 28 November 2010 near apparent magnitude 21.3.[3] The primary component 73P-C will come to perihelion (closest approach to the Sun) on 16 October 2011.[2]
Comet Schwassmann–Wachmann 3, one of the comets discovered by astronomers by Arnold Schwassmann and Arno Arthur Wachmann, working at the Hamburg Observatory in Bergedorf, Germany, broke into fragments on its re-entry to the inner solar system, May 1, 2006, in a reaction triggered by the sun's heating the comet as it emerged from the frozen space of the outer solar system.
Comet 73P is a parent body of meteor shower Tau Herculids.
The comet's initial discovery was serendipity: the astronomers were exposing photographic plates in search of minor planets, on photographs exposed for a minor planet survey, on May 2, 1930. The comet was lost after its 1930 apparition, but was observed several more times.
73P/Schwassmann–Wachmann has an orbital period of slightly less than 5 1/3 years so that it comes nearest to the Earth every 16 years. 73P was originally estimated to have a core diameter of 1100 meters.
Contents |
In 1995, 73P began to disintegrate.[4] It was seen to break into four large pieces labeled 73P-A, B, C, & D.[5] As of March 2006, at least eight fragments were known: B, C, G, H, J, L, M & N. On April 18, 2006, the Hubble Space Telescope recorded dozens of pieces of fragments B and G. It appears that the comet may eventually disintegrate completely and cease to be observable (as did 3D/Biela in the 19th century), in which case its designation would change from 73P to 73D. It is now known to have split into at least 66 separate objects.[6] Nuclei C is the largest and the presumed principal remnant of the original nucleus.[5]
The fragments were passing the Earth in late April and early May 2006, coming nearest to the Earth around May 12 at a distance of about 11.9 million km (7.4 million miles). That is a close pass in astronomical terms (0.08 AU) though nothing to be concerned about. In 1930 when it passed the Earth this close, there were meteor showers with as many as 100 meteors per minute. However, recent analysis by P. A. Wiegert et al.[7] suggests that a recurrence of this spectacle is unlikely.
In 2022, the comet fragments are expected to pass nearer to the Earth than in 2006. If the fragments continue to break up, it may become impossible to track all of them since each time a fragment splits, the resulting sub-fragments are fainter and have divergent trajectories.
The comet was to be visited by the CONTOUR comet nucleus probe on June 18, 2006. Unfortunately, the probe was destroyed due to a rocket malfunction during launch.
| Periodic comets (by number) | ||
|---|---|---|
| Previous 72P/Denning–Fujikawa |
73P/Schwassmann–Wachmann | Next 74P/Smirnova–Chernykh |
