(15875) 1996 TP66

(15875) 1996 TP66
Orbital diagram with 1996 TP66 being well inside the orbit of Neptune as of 2008
Discovered byJ. X. Luu
D. C. Jewitt
C. Trujillo
Discovery siteMauna Kea Obs.
Discovery date11 October 1996
(15875) 1996 TP66
1996 TP66
TNO[2] · plutino[3][4]
Orbital characteristics[2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 3
Observation arc12.03 yr (4,394 d)
Aphelion51.960 AU
Perihelion26.317 AU
39.139 AU
244.86 yr (89,435 d)
0° 0m 14.4s / day
Physical characteristics
Mean diameter
154±34 km[4][5]
B–V = 1.050[6]
V–R = 0.660[6]
V–I = 1.310[6]

(15875) 1996 TP66, provisional designation 1996 TP66, is a resonant trans-Neptunian object of the plutino population, located in the outermost region of the Solar System, approximately 154 kilometers (96 miles) in diameter. It was discovered on 11 October 1996, by astronomers Jane Luu, David C. Jewitt and Chad Trujillo at the Mauna Kea Observatories, Hawaii, in the United States.[1] The very reddish RR-type with a highly eccentric orbit has been near its perihelion around the time of its discovery. This minor planet was numbered in 2000 and has since not been named. It is probably not a dwarf planet candidate.

Orbit and classification[]

Plutino Resonance: motion of 1996 TP66 (red) and Pluto (grey) in a rotating frame with Neptune held stationary (equal to its orbital period)
Distance to the Sun for 1996 TP66 (orange) Pluto (blue), and Neptune (pink) over a 1,000 year period

1996 TP66 belongs to the dynamical population of plutinos, named after its largest member, Pluto. Plutinos are resonant trans-Neptunian objects in a 2:3 orbital resonance with Neptune, 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 high eccentricity of 0.33 and an inclination of 6° with respect to the ecliptic.[2] Among the plutinos, 1996 TP66 has one of the most elliptical orbits, with a perihelion almost halfway between Uranus (19.2 AU) and Neptune (30.1 AU). The body's observation arc begins with its official discovery observation at Mauna Kea in October 1996.[1] Calculations by the Minor Planet Center in 1997 showed that the eccentric orbit of 1996 TP66 comes within 6.9 AU of Uranus and stays more than 22.6 AU from Neptune over a 14,000-year period centered on the present.[11]

Inside Neptune's orbit[]

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 the Deep Ecliptic Survey (DES) show that over the next 10 million years 1996 TP66 can acquire a perihelion distance (qmin) as small as 25.9 AU.[3] Objects like Huya and the plutino 2004 EW95 are also currently inside the orbit of Neptune.

Numbering and naming[]

This minor planet was numbered by the Minor Planet Center on 26 July 2000 and received the number 15875 in the minor planet catalog (M.P.C. 40993).[12] As of 2018, it has not been named.[1]

Physical properties[]

1996 TP66 has a RR 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 featureless infrared spectrum.[8][13] In 2015, Irina Belskaya published the following color 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 the Herschel Space Observatory (Mommert): B–V (1.030), V–R (0.660) and V–I (1.320),[5] and also agree with previous measurements by Olivier 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 the Small Body Data Ferret.[16]

Diameter and albedo[]

According to the survey carried out by the Herschel Space Telescope using its PACS instrument, 1996 TP66 measures 154.0+28.8
kilometers in diameter and its surface has an albedo of 0.074+0.063
.[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 to Michael Brown, it is "probably not" a dwarf planet candidate, due to its relatively small diameter estimated at 158 kilometers.[18] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and derives a diameter of 139.81 kilometers based on an absolute magnitude of 7.39.[9]

Rotation period[]

1996 TP66 was part of a rotational lightcurve study which was published in the journal Nature in 1999. The photometric observations gave a brightness variation of no more than 0.12 magnitude, which is indicative of a rather spherical shape.[10][16] As of 2018, the body's rotation period and pole remain unknown.[9]


  1. ^ a b c d e f "15875 (1996 TP66)". Minor Planet Center. Retrieved 6 November 2018.
  2. ^ a b c d e "JPL Small-Body Database Browser: 15875 (1996 TP66)" (2008-10-22 last obs.). Jet Propulsion Laboratory. Retrieved 6 November 2018.
  3. ^ a b Marc W. Buie. "Orbit Fit and Astrometric record for (15875)". Southwest Research Institute. Retrieved 6 November 2018.
  4. ^ a b c d e Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 6 November 2018.
  5. ^ a b c d e Mommert, M.; Harris, A. W.; Kiss, C.; Pál, A.; Santos-Sanz, P.; Stansberry, J.; et al. (May 2012). "TNOs are cool: A survey of the trans-Neptunian region. V. Physical characterization of 18 Plutinos using Herschel-PACS observations". Astronomy and Astrophysics. 541: 17. arXiv:1202.3657. Bibcode:2012A&A...541A..93M. doi:10.1051/0004-6361/201118562. S2CID 119253817.
  6. ^ a b c d e f Belskaya, Irina N.; Barucci, Maria A.; Fulchignoni, Marcello; Dovgopol, Anatolij N. (April 2015). "Updated taxonomy of trans-neptunian objects and centaurs: Influence of albedo". Icarus. 250: 482–491. Bibcode:2015Icar..250..482B. doi:10.1016/j.icarus.2014.12.004.
  7. ^ a b "Asteroid (15875) 1996TP66 – Ephemerides". AstDyS-2, Asteroids – Dynamic Site. Retrieved 6 November 2018.
  8. ^ a b Doressoundiram, A.; Peixinho, N.; Moullet, A.; Fornasier, S.; Barucci, M. A.; Beuzit, J.-L.; et al. (December 2007). "The Meudon Multicolor Survey (2MS) of Centaurs and Trans-Neptunian Objects: From Visible to Infrared Colors". The Astronomical Journal. 134 (6): 2186–2199. Bibcode:2007AJ....134.2186D. doi:10.1086/522783.
  9. ^ a b c "LCDB Data for (15875)". Asteroid Lightcurve Database (LCDB). Retrieved 6 November 2018.
  10. ^ a b Romanishin, W.; Tegler, S. C. (March 1999). "Rotation rates of Kuiper-belt objects from their light curves". Nature. 398 (6723): 129–132. Bibcode:1999Natur.398..129R. doi:10.1038/18168. S2CID 4313184.
  11. ^ "MPEC 1997-N03: 1996 TP66". Minor Planet Center. 2 July 1997. Retrieved 6 November 2018.
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 6 November 2018.
  13. ^ Barkume, K. M.; Brown, M. E.; Schaller, E. L. (January 2008). "Near-Infrared Spectra of Centaurs and Kuiper Belt Objects". The Astronomical Journal. 135 (1): 55–67. Bibcode:2008AJ....135...55B. doi:10.1088/0004-6256/135/1/55.
  14. ^ Hainaut, O. R.; Boehnhardt, H.; Protopapa, S. (October 2012). "Colours of minor bodies in the outer solar system. II. A statistical analysis revisited". Astronomy and Astrophysics. 546: 20. arXiv:1209.1896. Bibcode:2012A&A...546A.115H. doi:10.1051/0004-6361/201219566. S2CID 54776793.
  15. ^ Hainaut, O. R.; Delsanti, A. C. (July 2002). "Colors of Minor Bodies in the Outer Solar System. A statistical analysis". Astronomy and Astrophysics. 389 (2): 641–664. Bibcode:2002A&A...389..641H. doi:10.1051/0004-6361:20020431.
  16. ^ a b "Asteroid (15875) 1996 TP66". Small Bodies Data Ferret. Retrieved 6 November 2018.
  17. ^ Stansberry, J. A.; Cruikshank, D. P.; Grundy, W. G.; Margot, J. L.; Emery, J. P.; Fernandez, Y. R.; et al. (August 2005). "Albedos, Diameters (and a Density) of Kuiper Belt and Centaur Objects". American Astronomical Society. 37: 737. Bibcode:2005DPS....37.5205S.
  18. ^ Brown, Michael E. "How many dwarf planets are there in the outer solar system?". California Institute of Technology. Retrieved 6 November 2018.

External links[]