(26375) 1999 DE9

(26375) 1999 DE₉
Discovery
Discovered by	Chadwick A. Trujillo and Jane X. Luu
Discovery date	20 February 1999
Designations
MPC designation	(26375) 1999 DE₉
Minor planet category	TNO 2:5 resonance^[1]
Orbital characteristics^[2]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 2
Observation arc	6619 days (18.12 yr)
Aphelion	79.663 AU (11.9174 Tm)
Perihelion	32.342 AU (4.8383 Tm)
Semi-major axis	56.002 AU (8.3778 Tm)
Eccentricity	0.42249
Orbital period (sidereal)	419.10 yr (153075 d)
Average orbital speed	3.81 km/s
Mean anomaly	25.385°
Mean motion	0° 0^m 8.466^s / day
Inclination	7.6076°
Longitude of ascending node	322.909°
Argument of perihelion	160.236°
Earth MOID	31.3582 AU (4.69112 Tm)
Jupiter MOID	27.062 AU (4.0484 Tm)
Physical characteristics
Dimensions	461 ± 45 km^[3]
Synodic rotation period	24 h (1.0 d)
Geometric albedo	0.06–0.08^[3]
Temperature	≈37 K
Absolute magnitude (H)	5.0

(26375) 1999 DE₉ (provisional designation 1999 DE₉) is a trans-Neptunian object. Light-curve-amplitude analysis shows only small deviations, suggesting (26375) 1999 DE₉ is a spheroid with small albedo spots.^[4] Measurements by the Spitzer Space Telescope estimate that it is 461 ± 45 km in diameter.^[3] It was discovered in 1999 by Chad Trujillo and Jane X. Luu. It is possibly a dwarf planet.^[5]

(26375) 1999 DE₉ orbit is in 2:5 resonance with Neptune's.^[1] Spectral analysis has shown traces of ice.^[6]

References

^ ^a ^b Marc W. Buie (March 14, 2008). "Orbit Fit and Astrometric record for 26375". SwRI (Space Science Department). Retrieved September 24, 2008.
^ "JPL Small-Body Database Browser: 26375 (1999 DE9)". NASA/Jet Propulsion Laboratory. Retrieved April 5, 2016.
^ ^a ^b ^c Stansberry, Grundy, Brown, Spencer, Trilling, Cruikshank, Luc Margot Physical Properties of Kuiper Belt and Centaur Objects: Constraints from Spitzer Space Telescope (2007) arXiv:astro-ph/0702538
^ Tancredi, G., & Favre, S. (2008) Which are the dwarfs in the Solar System?. Depto. Astronomía, Fac. Ciencias, Montevideo, Uruguay; Observatorio Astronómico Los Molinos, MEC, Uruguay. Retrieved August 10, 2011
^ Icy Dwarf Planets and TNOs
^ Fig 3 for 1999 DE9

v t e Minor planets navigator
(26374) 1999 CP106 (26375) 1999 DE₉ 26376 Roborosa

Designation Groups List Moon Meanings of names
Asteroid	Active Aten asteroid Asteroid belt Family Jupiter trojan Near-Earth Spectral types
Distant minor planet	Cis-Neptunian object Centaur Neptune trojan Damocloid Trans-Neptunian object Detached Kuiper belt Oort cloud Scattered disc

Other

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Rings	Jovian Saturnian (Rhean) Charikloan Chironean Uranian Neptunian Haumean Quaoarian
Small Solar System Bodies	Comets Damocloids Meteoroids Minor planets names and meanings moons Planetesimal Planetary orbit-crossing minor planets Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Trojans Venus Earth Mars Jupiter Trojan camp Greek camp Saturn Moons Uranus Neptune Near-Earth objects Asteroid belt Asteroids Ceres Vesta Pallas Hygiea active first 1000 families PHA exceptional Kirkwood gap Cis-Neptunian objects Centaurs Neptune trojans Trans-Neptunian objects Kuiper belt Cubewanos Plutinos Detached objects Sednoids Scattered disc Oort cloud Hills cloud

Hypothetical objects	Fifth giant Nemesis Phaeton Planet Nine Planet V Planet X Subsatellites Theia Tyche Vulcan Vulcanoids
Exploration (outline)	Colonization Discovery astronomy historical models timeline Space probes timeline list Human spaceflight space stations list programs Mercury Venus Moon mining Mars Ceres Asteroids mining Comets Jupiter Saturn Uranus Neptune Pluto Deep space
Formation and evolution	Star formation Accretion Accretion disk Excretion disk Circumplanetary disk Circumstellar disc Circumstellar envelope Coatlicue Cosmic dust Debris disk Detached object EXCEDE Exozodiacal dust Extraterrestrial materials Sample curation Sample-return mission Frost/Ice/Snow line Giant-impact hypothesis Gravitational collapse Hills cloud Hill sphere Interplanetary dust cloud Interplanetary medium/space Interstellar cloud Interstellar medium Interstellar space Kuiper belt Kuiper cliff Molecular cloud Nebular hypothesis Oort cloud Outer space Planet Disrupted Migration System Planetesimal Formation Merging stars Protoplanetary disk Ring system Roche limit vs. Hill sphere Rubble pile Scattered disc
Lists	Comets Possible dwarf planets Gravitationally rounded objects Minor planets Natural satellites Solar System models Solar System objects by size by discovery date Interstellar and circumstellar molecules
Related	Double planet Lagrangian points Moonlets Syzygy Tidal locking

Consensus	Ceres
Possible	Hygiea Interamnia

Possible	Chariklo Chiron 2013 TC₁₄₆ 2014 NW₆₅

Consensus	Orcus Pluto
Possible	Huya Ixion 2001 QF₂₉₈ 2002 VR₁₂₈ 2002 XV₉₃ 2003 AZ₈₄ 2003 UZ₄₁₃ 2003 VS₂ 2007 JH₄₃ 2017 OF69

Possible	2002 WC₁₉

Cubewanos and
other Kuiper belt

Consensus	Haumea Makemake Quaoar
Possible (cubewanos)	Chaos Salacia Varda Varuna 1998 SN₁₆₅ 2002 AW₁₉₇ 2002 CY248 2002 KX₁₄ 2002 MS₄ 2002 UX₂₅ 2003 QW₉₀ 2004 GV₉ 2004 NT₃₃ 2004 PF₁₁₅ 2004 TY₃₆₄ 2004 UX₁₀ 2005 RN₄₃ 2005 UQ₅₁₃ 2010 FX86
Possible (other)	1999 CD₁₅₈ 1999 DE₉ 2000 YW₁₃₄ 2002 XW₉₃ 2010 JO₁₇₉ 2010 VK₂₀₁ 2011 FW62 2011 GM₂₇ 2013 FZ₂₇ 2014 UM₃₃ 2015 AM₂₈₁ 2015 RR₂₄₅