Chad Trujillo in the context of Minor planet

Orcus (minor-planet designation: 90482 Orcus) is a dwarf planet located in the Kuiper belt, with one large moon, Vanth. It has an estimated diameter of 870 to 960 km (540 to 600 mi), comparable to the Inner Solar System dwarf planet Ceres. The surface of Orcus is relatively bright with albedo reaching 23 percent, neutral in color, and rich in water ice. The ice is predominantly in crystalline form, which may be related to past cryovolcanic activity. Other compounds like methane or ammonia may also be present on its surface. Orcus was discovered by American astronomers Michael Brown, Chad Trujillo, and David Rabinowitz on 17 February 2004.

Orcus is a plutino, a trans-Neptunian object that is locked in a 2:3 orbital resonance with the ice giant Neptune, making two revolutions around the Sun to every three of Neptune's. This is much like Pluto, except that the phase of Orcus's orbit is opposite to Pluto's: Orcus is at aphelion (most recently in 2019) around when Pluto is at perihelion (most recently in 1989) and vice versa. Orcus is the second-largest known plutino, after Pluto itself. The perihelion of Orcus's orbit is around 120° from that of Pluto, while the eccentricities and inclinations are similar. Because of these similarities and contrasts, along with its large moon Vanth that can be compared to Pluto's large moon Charon, Orcus has been dubbed the "anti-Pluto". This was a major consideration in selecting its name, as the deity Orcus was the Roman/Etruscan equivalent of the Roman/Greek Pluto.

Quaoar (minor-planet designation: 50000 Quaoar) is a ringed dwarf planet in the Kuiper belt, a band of icy planetesimals beyond Neptune. It has a slightly ellipsoidal shape with an average diameter of 1,100 km (680 mi), about half the size of the dwarf planet Pluto. The object was discovered by American astronomers Chad Trujillo and Michael Brown at Palomar Observatory on 4 June 2002. Quaoar has a reddish surface made of crystalline water ice, tholins, and traces of frozen methane.

Quaoar has two thin rings orbiting outside its Roche limit, which defied initial theoretical expectations that rings outside the Roche limit should be unstable. Quaoar has one moon named Weywot and another unnamed moon that has not yet been confirmed. It is believed that Quaoar's elongated shape, gravitational influence of its moons, and extremely cold temperature help keep its rings stable.

Makemake (minor-planet designation: 136472 Makemake) is a dwarf planet in the Kuiper belt, a disk of icy bodies beyond the orbit of Neptune. It is the fourth largest trans-Neptunian object and the largest member of the classical Kuiper belt, having a diameter 60% that of Pluto. It was discovered on March 31, 2005 by American astronomers Michael E. ("Mike") Brown, Chad Trujillo, and David Rabinowitz at Palomar Observatory. As one of the largest objects found by this team, the discovery of Makemake contributed to the reclassification of Pluto as a dwarf planet in 2006.

Makemake is similar to Pluto with respect to its surface: it is highly reflective, covered largely by frozen methane, and stained reddish-brown by tholins. Makemake has one known satellite, which has not been named. The orbit of this satellite suggests that Makemake's rotation has a high axial tilt, which implies that it experiences extreme seasons. Makemake shows evidence of geochemical activity and cryovolcanism, which has led scientists to suspect that it might harbor a subsurface ocean of liquid water. Gaseous methane has been found on Makemake, although it is unclear whether it is contained in an atmosphere or comes from temporary outgassing.

2018 AG₃₇ is a distant trans-Neptunian object and centaur that was discovered 132.2 ± 1.5 AU (19.78 ± 0.22 billion km) from the Sun, farther than any other currently observable known object in the Solar System. Imaged in January 2018 during a search for the hypothetical Planet Nine, the confirmation of this object was announced in a press release in February 2021 by astronomers Scott Sheppard, David Tholen, and Chad Trujillo. The object was nicknamed "FarFarOut" to emphasize its distance from the Sun.2018 AG₃₇ was discovered when it was near aphelion, the farthest point from the Sun in its elliptical orbit. The object is estimated to be at least 400 km (250 mi) in diameter. Because of its extreme distance, 2018 AG₃₇ appears extremely faint with an apparent magnitude of 25—only visible to the largest telescopes in the world.

2018 VG₁₈ is a distant trans-Neptunian object (TNO) that was discovered when it was 123 AU (18 billion km; 11 billion mi) from the Sun, more than three times the average distance between the Sun and Pluto. It was discovered on 10 November 2018 by Scott Sheppard, David Tholen, and Chad Trujillo during their search for TNOs whose orbits might be gravitationally influenced by the hypothetical Planet Nine. They announced the discovery of 2018 VG₁₈ on 17 December 2018 and nicknamed the object "Farout" to emphasize its distance from the Sun.

2018 VG₁₈ is the second-most distant natural object ever observed in the Solar System, after 2018 AG37 (132 AU), which was also discovered by Sheppard's team in January 2018. As of 2024, 2018 VG₁₈ is 123.6 AU (18 billion km) from the Sun and is moving farther away until it reaches aphelion in 2063. While 2018 VG₁₈ is one of the most distant Solar System objects known, its orbit is not the most distant since its average orbital distance from the Sun is 82 AU, which places it in the scattered disk and the 2:9 orbital resonance with Neptune.

341520 Mors–Somnus (/ˌmɔːrs ˈsɒmnəs/; provisional designation 2007 TY₄₃₀) is a binary and plutino. It consists of two components less than 60 kilometers in diameter, orbiting at a distance of 21000 km.

Mors–Somnus was discovered on 14 October 2007, by American astronomers Scott Sheppard and Chad Trujillo with the Subaru Telescope at Mauna Kea Observatories in Hawaii, United States. It was later named after the twins Mors and Somnus from Roman mythology.

Quaoar (minor-planet designation: 50000 Quaoar) is a ringed dwarf planet in the Kuiper belt, a band of icy planetesimals beyond Neptune. It has a slightly ellipsoidal shape with an average diameter of 1,100 km (680 mi), about half the size of the dwarf planet Pluto. The object was discovered by American astronomers Chad Trujillo and Michael Brown at Palomar Observatory on 4 June 2002. Quaoar has a reddish surface made of crystalline water ice, tholins, and traces of frozen methane.

Quaoar has two thin rings orbiting outside its Roche limit, which defies theoretical expectations that rings outside the Roche limit should be unstable. Quaoar has one moon named Weywot and another unnamed moon that has not yet been confirmed. It is believed that Quaoar's elongated shape, gravitational influence of its moons, and extremely cold temperature help keep its rings stable.

2012 VP₁₁₃ is a trans-Neptunian object (TNO) orbiting the Sun on an extremely wide elliptical orbit. It is classified as a sednoid because its orbit never comes closer than 80.5 AU (12.04 billion km; 7.48 billion mi) from the Sun, which is far enough away from the giant planets that their gravitational influence cannot affect the object's orbit noticeably. It was discovered on 5 November 2012 at Cerro Tololo Inter-American Observatory in Chile, by American astronomers Scott Sheppard and Chad Trujillo, who nicknamed the object "Biden" because of its "VP" abbreviation. The discovery was announced on 26 March 2014. The object's diameter has not been measured, but its brightness suggests it is around 450 km (280 mi) in diameter. 2012 VP₁₁₃ has a reddish color similar to many other TNOs.

2012 VP₁₁₃ has not yet been imaged by high-resolution telescopes, so it has no known moons. The Hubble Space Telescope is planned to image 2012 VP₁₁₃ in 2026, which should determine if it has significantly sized moons.

2021 RR₂₀₅ is an extreme trans-Neptunian object discovered by astronomers Scott Sheppard, David Tholen, and Chad Trujillo with the Subaru Telescope at Mauna Kea Observatory on 5 September 2021. It resides beyond the outer extent of the Kuiper belt on a distant and highly eccentric orbit detached from Neptune's gravitational influence, with a large perihelion distance of 55.5 astronomical units (AU). Its large orbital semi-major axis (~1,000 AU) suggests it is potentially from the inner Oort cloud. 2021 RR₂₀₅ and 2013 SY99 both lie in the 50–75 AU perihelion gap that separates the detached objects from the more distant sednoids; dynamical studies indicate that such objects in the inner edge of this gap weakly experience "diffusion", or inward orbital migration due to minuscule perturbations by Neptune. While Sheppard considers 2021 RR₂₀₅ a sednoid, researchers Yukun Huang and Brett Gladman do not.

2021 RR₂₀₅'s heliocentric distance was 60 AU when it was discovered. It has been detected in precovery observations by the Dark Energy Survey at Cerro Tololo Observatory from as early as July 2017. It last passed perihelion in the early 1990s and is now moving outbound from the Sun.

208996 Achlys (provisional designation 2003 AZ₈₄) is a large trans-Neptunian object orbiting the Sun in the Kuiper belt, a region of icy bodies beyond Neptune. It was discovered on 13 January 2003 by Chad Trujillo and Michael E. Brown at Palomar Observatory. Achlys has an elongated shape that is believed to be distorted by its rapid 6.8-hour rotation. Its diameter is estimated to be roughly 940 km (580 mi) across its equator to 490 km (300 mi) across its poles. After Pluto and Orcus, Achlys is the third largest member of the plutinos—a population of Kuiper belt objects following a 2:3 orbital resonance with Neptune, in which they complete two orbits for every three orbits completed by Neptune.

The surface of Achlys is dark gray and mostly composed of water ice. Observations of stellar occultations show that Achlys's surface bears a chasm or depression between 8 and 13 km (5.0 and 8.1 mi) deep, similar to those seen on Pluto and its moon Charon. Achlys has one known moon that is about 80 km (50 mi) in diameter. The mass and density of Achlys has not been measured, though predictions based on its shape and rotation suggest that it has a density lower than that of water ice.

(612243) 2001 QR₃₂₂, prov. designation: 2001 QR₃₂₂, is a minor planet and the first Neptune trojan discovered, by American astronomer Marc Buie of the Deep Ecliptic Survey at Cerro Tololo Observatory in Chile on 21 August 2001. It orbits ahead of Neptune at its L₄ Lagrangian point and measures approximately 132 kilometers (82 miles) in diameter.

Other Neptune trojans have been discovered since. A study by American astronomers Scott Sheppard and Chad Trujillo from the Carnegie Institution suggests that Neptune could possibly have twenty times more trojans than Jupiter.

2005 TN₅₃ is an inclined Neptune trojan leading Neptune's orbit in the outer Solar System, approximately 80 kilometers in diameter. It was first observed on 7 October 2005, by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory in the Atacama desert of Chile. It was the third such body to be discovered, and the first with a significant orbital inclination, which showed that the population as a whole is very dynamically excited.

307261 Máni (provisional designation 2002 MS₄) is a large trans-Neptunian object in the Kuiper belt, a region of icy planetesimals beyond Neptune. It was discovered on 18 June 2002 by Chad Trujillo and Michael Brown during their search for Pluto-sized Kuiper belt objects at Palomar Observatory. With a diameter of about 800 km (500 mi), Máni is large enough that some astronomers believe that it might be a dwarf planet.

The surface of Máni is dark gray and is composed of water and carbon dioxide ices. Máni has been observed through stellar occultations, which have revealed massive topographic features along the outline of its shape. These features include a mountain-like peak that is 25 km (16 mi) tall and a crater-like depression that is 320 km (200 mi) wide and 45 km (28 mi) deep. Máni's topographic features are among the tallest and deepest known for Solar System bodies.

532037 Chiminigagua (provisional designation 2013 FY₂₇) is a large trans-Neptunian object in the scattered disc. It was discovered on 17 March 2013 by Scott Sheppard and Chad Trujillo at Cerro Tololo Observatory in Chile. Chiminigagua has a nominal diameter of about 740 km (460 mi), which is large enough that some astronomers consider it a possible dwarf planet. Chiminigagua has a moderately red color, which suggests it has an old, ice-poor surface that has been dulled by cosmic rays and micrometeoroid bombardment. It has one unnamed moon about 190 km (120 mi) in diameter, which is believed to have formed from a giant impact on Chiminigagua.

(84522) 2002 TC₃₀₂ (provisional designation 2002 TC₃₀₂) is a mid-sized trans-Neptunian object located in the outermost region of the Solar System. It was discovered on 9 October 2002, by American astronomers Mike Brown, Chad Trujillo and David Rabinowitz at the Palomar Observatory in California. The resonant trans-Neptunian object stays in a 2:5 resonance with Neptune. It has a reddish color, a rotation period of 56.1 hours and measures at least 500 kilometers (310 miles) in diameter.