(181708) 1993 FW
(181708) 1993 FW (provisional designation 1993 FW) is a cubewano and was the second trans-Neptunian object to be discovered after Pluto and Charon, the first having been 15760 Albion, formerly known as (15760) 1992 QB1. It was discovered in 1993 by David C. Jewitt and Jane X. Luu at the Mauna Kea Observatory, Hawaii. Following its discovery it was nicknamed "Karla" after a character by John le Carré by its discoverers and was hailed as that of a new planet. Mike Brown lists it as possibly a dwarf planet on his website.
| Discovery | |
|---|---|
| Discovered by | David C. Jewitt, Jane X. Luu |
| Discovery date | 28 March 1993 |
| Designations | |
Minor planet category | Trans-Neptunian object (cubewano) |
| Orbital characteristics | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 5456 days (14.94 yr) |
| Aphelion | 46.293 AU (6.9253 Tm) |
| Perihelion | 41.642 AU (6.2296 Tm) |
Semi-major axis | 43.967 AU (6.5774 Tm) |
| Eccentricity | 0.052899 |
Orbital period (sidereal) | 291.54 yr (106487 d) |
Average orbital speed | 4.489 km/s |
Mean anomaly | 351.305° |
Mean motion | 0° 0m 12.171s / day |
| Inclination | 7.7336° |
Longitude of ascending node | 187.837° |
| 40.180° | |
| Jupiter MOID | 36.2333 AU (5.42042 Tm) |
| Physical characteristics | |
| Dimensions | 175 km 241 km |
| 7.0 | |
181708 was discovered half a year after Albion.
Over one thousand bodies were found in a belt orbiting between about 30-50 AU from the Sun in the twenty years (1992-2012), after finding 1992 QB1 (named in 2018, 15760 Albion), showing a vast belt of bodies more than just Pluto and Albion. By 2018, over 2000 Kuiper belts objects were discovered.
The mid-1990s were a time when the new region "came to life", triggering a retrospective of various predictions about second asteroid or comet belts in the outer solar system.
Three more KBOs found in 1993 are (15788) 1993 SB, (15789) 1993 SC, and (385185) 1993 RO.