11P/Tempel–Swift–LINEAR
Periodic comet
From Wikipedia, the free encyclopedia
11P/TempelâSwiftâLINEAR is a periodic comet roughly 1 km in diameter with a 5.95-year orbit around the Sun. At the perihelion passage on 9 November 2026 the solar elongation will be 170 degrees.[6] The closest approach to Earth will be two days later on 11 November 2026 at a distance of 0.401 AU (60.0 million km).[2][6][a] The comet may brighten enough in late 2026 to get into the reach of smart telescopes.
- 27 November 1869
- 11 October 1880
- 7 December 2001
- P/1869 W1, P/1880 T1
- P/2001 X3
- 1869 III, 1880 IV
- 1891 V, 1908 II
- 1869c, 1880e, 1891d
- 1908d
Infrared image of Comet TâSâL taken by NEOWISE on 4 January 2021. | |
| Discovery[1] | |
|---|---|
| Discovered by | |
| Discovery date |
|
| Designations | |
| |
| |
| Orbital characteristics[2][3] | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Observation arc | 154.75 years |
| Number of observations | 1,337 |
| Aphelion | 5.18 AU |
| Perihelion | 1.387 AU |
| Semi-major axis | 3.283 AU |
| Eccentricity | 0.57739 |
| Orbital period | 5.95 years |
| Inclination | 14.432° |
| 238.86° | |
| Argument of periapsis | 168.06° |
| Mean anomaly | 301.36° |
| Last perihelion | 26 November 2020[3] |
| Next perihelion | 9 November 2026[4] |
| TJupiter | 2.839 |
| Earth MOID | 0.403 AU (60.3 million km) |
| Jupiter MOID | 0.326 AU (48.8 million km) |
| Physical characteristics[2] | |
Mean radius | 0.6 km (0.37 mi)[5] |
| Comet total magnitude (M1) | 15.2±0.7 |
| Comet nuclear magnitude (M2) | 18.6 |
Observational history
Discovery
In 1869, the comet's perihelion was around 1.063 AU (159.0 million km) from the Sun.[7] Ernst Wilhelm Leberecht Tempel originally discovered the comet on 27 November 1869, from his observatory at Marseille. It was later observed by Lewis Swift from the Warner Observatory on 11 October 1880, and he realised that it is the same comet as Tempel's.[8]
Loss and recovery
After 1908, the comet became an unobservable lost comet due to a series of four close flybys of Jupiter between 1911 and 1946[b] perturbing its orbit significantly enough that made subsequent apparitions of the comet unfavorable for observations in decades.[9] Nevertheless, Brian G. Marsden computed the resulting orbit based on the observations between 1891 and 1908, and predicted a favorable return in 1963, however the comet remained unobserved.[9] Despite this, additional predictions of the comet's favorable returns were later attempted by Marsden and Zdenek Sekanina in 1971,[10] and Shuichi Nakano in 1995.
On 7 December 2001, an object designated as P/2001 X3 was found by the Lincoln Near-Earth Asteroid Research (LINEAR) program.[11] Analysis of images taken between 10 September and 17 October 2001 later confirmed that P/2001 X3 was the recovery of the previously lost comet TempelâSwift.[1]
Recent observations
The comet was not observed during the 2008 unfavorable apparition because the perihelion passage occurred when the comet was on the far side of the Sun.[12][3] The comet was observed during the 2014 and 2020 apparitions.[3] The comet will next come to perihelion on 9 November 2026,[4] then two days later on the 11th, make a closest approach to Earth of 0.4012 AU (60.02 million km).[2]
2104
| Date & time of closest approach |
Earth distance (AU) |
Sun distance (AU) |
Velocity wrt Earth (km/s) |
Velocity wrt Sun (km/s) |
Uncertainty region (3-sigma) |
Reference |
|---|---|---|---|---|---|---|
| 2104-Nov-14 17:17 | 0.318 AU (47.6 million km; 29.6 million mi) | 1.28 AU (191 million km; 119 million mi) | 9.5 | 33.2 | ± 1137 km | Horizons |
Notes
- The 2026 Earth approach of 0.401 AU (60.0 million km) is closer than the (Epoch 2019) EarthâMinimum orbit intersection distance (MOID) of 0.403 AU (60.3 million km).