 4015 Wilson–Harrington at 19 November 1949, from the 48-inch Schmidt telescope at Palomar. The image was enhanced by ESO to show the tail. | |
| Discovery | |
|---|---|
| Discovered by | Albert G. Wilson and Robert G. Harrington |
| Discovery date | 19 November 1949 |
| Designations | |
| (4015) Wilson–Harrington | |
| 107P/1949 W1 107P/1979 VA 1949 III · 1949g | |
| NEO · Apollo · Comet | |
| Orbital characteristics[1] | |
| Epoch 2022-Aug-09 (JD 2459800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 24241 days (66.37 yr) |
| Aphelion | 4.2833 AU (640.77 Gm) |
| Perihelion | 0.96664 AU (144.607 Gm) |
| 2.6249 AU (392.68 Gm) | |
| Eccentricity | 0.63175 |
| 4.25yr (1553.4d) | |
Averageorbital speed | 16.39 km/s |
| 356.37° | |
| 0° 13m 47.568s / day | |
| Inclination | 2.7992° |
| 266.77° | |
| 2026-Nov-25[2] 2022-Aug-24 (previous) | |
| 95.441° | |
| Earth MOID | 0.045552 AU (6.8145 Gm) |
| TJupiter | 3.080 |
| Physical characteristics | |
| Dimensions | 4 km |
| 2 ± 0.25 km | |
| 3.5736 h (0.14890 d) | |
| 0.05 ± 0.01 | |
| (orange) B−V=0.666 U−B=0.279 | |
| ~11 (1979) 16 (2009)[3] | |
| 15.99 | |
4015 Wilson–Harrington is anactive asteroid[4] known both ascomet107P/Wilson–Harrington and asasteroid4015 Wilson–Harrington. It passed 0.4 AU (60 million km) from Earth on 20 July 2022 and then passedperihelion (closest approach to the Sun) on 24 August 2022.[1] It seldom gets brighter thanapparent magnitude 16.[3] It will return to perihelion on 25 November 2026.[2]
Thisnear-Earth object is considered both anApollo asteroid with the designation4015 Wilson–Harrington and a periodiccomet known asComet Wilson–Harrington or107P/Wilson–Harrington. It was initially discovered in 1949 as a comet and then lost to further observations. Thirty years later it was rediscovered as an asteroid, after which it took over a decade to determine that these observations were of the same object. Therefore, it has both a comet designation and an asteroid designation, and with a name length of 17 characters it is currently the asteroid with the longest name, having one more character than the 16-character limit imposed by theIAU.[5]
The comet was discovered on 19 November 1949, byAlbert G. Wilson andRobert G. Harrington atPalomar Observatory. Only three photographic observations were obtained and the comet waslost (insufficient observations to determine a precise enough orbit to know where to look for future appearances of the comet.)
On 15 November 1979, an apparentMars-crosser asteroid was found byEleanor F. Helin, also ofPalomar Observatory. It received the designation1979 VA, and when re-observed on 20 December 1988, received the permanent number 4015.
On 13 August 1992, it was reported that asteroid (4015) 1979 VA and comet 107P/Wilson–Harrington were the same object. By then, enough observations of the asteroid had accumulated to obtain a fairly precise orbit, and the search of old photographic plates for prediscovery images turned up the 1949 plates with the images of the lost comet.
Although the 1949 images show cometary features, all subsequent images appear stellar, suggesting it might be an inactive comet that undergoes only infrequent outbursts.
Theeccentricity is 0.624, which is somewhat higher than that of a typicalasteroid-beltminor planet and more typical of periodic comets. Its Minimum Orbit Intersection Distance (MOID) of less than 0.05 AU and its large size make it apotentially hazardous asteroid (PHA).
There are only eight other objects that are cross-listed as both comets and asteroids:2060 Chiron (95P/Chiron),7968 Elst–Pizarro (133P/Elst–Pizarro),60558 Echeclus (174P/Echeclus),118401 LINEAR (176P/LINEAR),(323137) 2003 BM80 (282P/2003 BM80),(300163) 2006 VW139 (288P/2006 VW139),(457175) 2008 GO98 (362P/2008 GO98),[6] and(248370) 2005 QN173 (433P/2005 QN173).[7] As a dual status object,astrometric observations of 4015 Wilson–Harrington should be reported under theminor planet designation.[6]
A flyby of 4015 Wilson–Harrington was formerly planned byDeep Space 1.[8] It was also considered for theNEAR mission.[9]
| Numbered comets | ||
|---|---|---|
| Previous 106P/Schuster | 4015 Wilson–Harrington | Next 108P/Ciffreo |
.png)
