 Orbital diagram with1996 TP66 being well inside the orbit ofNeptune as of 2008 | |
| Discovery[1] | |
|---|---|
| Discovered by | J. X. Luu D. C. Jewitt C. Trujillo |
| Discovery site | Mauna Kea Obs. |
| Discovery date | 11 October 1996 |
| Designations | |
| (15875)1996 TP66 | |
| 1996 TP66 | |
| TNO[2] · plutino[3][4] distant[1] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 3 | |
| Observation arc | 12.03yr (4,394 d) |
| Aphelion | 51.960AU |
| Perihelion | 26.317 AU |
| 39.139 AU | |
| Eccentricity | 0.3276 |
| 244.86 yr (89,435 d) | |
| 28.208° | |
| 0° 0m 14.4s / day | |
| Inclination | 5.7000° |
| 316.68° | |
| 74.784° | |
| Physical characteristics | |
| 154±34 km[4][5] | |
| 0.074[4][5] | |
| RR[6] B–V =1.050[6] V–R =0.660[6] V–I =1.310[6] | |
| 21.6[7] | |
| 6.79±0.33[8] 7.0[1][2] 7.39[9][10] 7.51±0.09[5] | |
(15875) 1996 TP66 (provisional designation1996 TP66) is a resonanttrans-Neptunian object of theplutino population, located in the outermost region of theSolar System, approximately 154 kilometers (96 miles) in diameter. It was discovered on 11 October 1996, by astronomersJane Luu,David C. Jewitt andChad Trujillo at theMauna Kea Observatories, Hawaii, in the United States.[1] The very reddishRR-type with a highlyeccentric orbit has been near itsperihelion around the time of its discovery. Thisminor planet was numbered in 2000 and has since not beennamed. It is probably not adwarf planet candidate due to its small size.
1996 TP66 belongs to the dynamical population ofplutinos, named after its largest member,Pluto. Plutinos areresonant trans-Neptunian objects in a 2:3orbital resonance withNeptune, which means that they orbit the Sun exactly twice while Neptune orbits the Sun three times.
It orbits the Sun at a distance of 26.3–52.0 AU once every 244 years and 10 months (89,435 days;semi-major axis of 39.14 AU). Its orbit has a notably higheccentricity of 0.33 and aninclination of 6° with respect to theecliptic.[2] Among the plutinos,1996 TP66 has one of the most elliptical orbits, with aperihelion almost halfway betweenUranus (19.2 AU) and Neptune (30.1 AU). The body'sobservation arc begins with its official discovery observation atMauna Kea in October 1996.[1] Calculations by theMinor Planet Center in 1997 showed that theeccentric orbit of1996 TP66 comes within 6.9 AU ofUranus and stays more than 22.6 AU from Neptune over a 14,000-year period centered on the present.[11]
In 2000, this object came closest to the Sun (perihelion) at 26.3 AU,[2] and has since moved away to a distance of 29.2 AU by the end of 2018.[7] This means that this small plutino is still well inside the orbit of Neptune which has a semi-major axis of 30.1 AU.
Like Pluto, this plutino spends part of its orbit closer to the Sun than Neptune. Like all resonant trans-Neptunian objects its orbit is dominated by Neptune. Simulations by theDeep Ecliptic Survey (DES) show that over the next 10 million years1996 TP66 can acquire a perihelion distance (qmin) as small as 25.9 AU.[3] Objects like the plutinosHuya and2004 EW95 are also currently inside the orbit of Neptune.
Thisminor planet wasnumbered by theMinor Planet Center on 26 July 2000 and received the number15875 in theminor planet catalog (M.P.C. 40993).[12] As of 2025, it has not beennamed.[1]
1996 TP66 has aRR taxonomic class,[4][6] with "very red" surface in the visible (rather than a "neutral" or "grey-blue" one for objects of the BB class) and a flat featurelessinfrared spectrum.[8][13] In 2015,Irina Belskaya published the followingcolor indices: B–V (1.050), V–R (0.660) and V–I (1.310).[6] The resulting B–R magnitude is 1.71.[4] These indices agree with the results obtained by theHerschel Space Observatory (Mommert): B–V (1.030), V–R (0.660) and V–I (1.320),[5] and also agree with previous measurements byOlivier Hainaut: B–V (1.031), V–R (0.655) and V–I (1.324),[14] as well as B–V (0.984), V–R (0.654) and V–I (11.337) from in 2012 and 2002, respectively.[15] The numerous results are summarized at theSmall Body Data Ferret.[16]
According to the survey carried out by theHerschel Space Telescope using itsPACS instrument,1996 TP66 measures154.0+28.8
−33.7 kilometers in diameter and its surface has analbedo of0.074+0.063
−0.031.[5] The results supersedes a previous study that gave a much larger diameter of 350 kilometers with a lower albedo of 0.03.[17] According toMichael Brown, it is "probably not" adwarf planet candidate, due to its relatively small diameter estimated at 158 kilometers.[18] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and derives a diameter of 139.81 kilometers based on anabsolute magnitude of 7.39.[9]
1996 TP66 was part of a rotationallightcurve study which was published in the journalNature in 1999. Thephotometric observations gave a brightness variation of no more than 0.12magnitude, which is indicative of a rather spherical shape.[10][16] As of 2018, the body'srotation period andpole remain unknown.[9]
