A critical-list minor planet (critical list numbered object or critical object) is a numbered minor planet for which existing measurements of the orbit and position are especially in need of improvement. [1]
The IAU's Minor Planet Center (MPC) regularly publishes a list of these critical objects in their Minor Planet Electronic Circular . [2] The list typically contains asteroids that have been observed at a small number of apparitions, especially on opposition, or that have not been adequately observed for more than 10 years, while other observatories create their own, customized lists. [3] The MPC also lists currently observable critical objects on their website, [4] providing differently formatted lists of orbital elements to the worldwide astrometric community. [5]
Lowell Observatory publishes their own critical list, distinctly different from the MPC, instead focusing on objects with high ephemeris uncertainty. Specifically, objects with computed ephemeris uncertainty greater than 2 arcseconds over the next 10 years, and objects whose orbits degrade significantly when temporally isolated observations are ignored, are included in the list. [3]
As of December 2024 [update] , the MPC includes 650 objects in their observable critical list. The following list contains all critical objects within the first 100,000 numbered minor planets, the full list can be found in the MPL website: [4] [6]
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Lowell Observatory Near-Earth-Object Search (LONEOS) was a project designed to discover asteroids and comets that orbit near the Earth. The project, funded by NASA, was directed by astronomer Ted Bowell of Lowell Observatory in Flagstaff, Arizona. The LONEOS project began in 1993 and ran until the end of February 2008.
20461 Dioretsa is a centaur and damocloid on a retrograde, cometary-like orbit from the outer Solar System. It was discovered on 8 June 1999, by members of the LINEAR team at the Lincoln Laboratory Experimental Test Site near Socorro, New Mexico, United States. The highly eccentric unusual object measures approximately 14 kilometers in diameter. It was named Dioretsa, an anadrome of "asteroid".
(48639) 1995 TL8 is a binary trans-Neptunian object from the scattered disc in the outermost regions of the Solar System. It was discovered by Arianna Gleason in 1995 and measures approximately 176 kilometers in diameter. Its 80-kilometer minor-planet moon, provisionally designated S/2002 (48639) 1, was discovered on 9 November 2002.
(119070) 2001 KP77 (provisional designation 2001 KP77) is a resonant trans-Neptunian object in the Kuiper belt, a circumstellar disc located in the outermost region of the Solar System. It was discovered on 23 May 2001, by American astronomer Marc Buie at the Cerro Tololo Observatory in Chile. The object is locked in a 4:7 orbital resonance with Neptune. It has a red surface color and measures approximately 176 kilometers (110 miles) in diameter. As of 2021, it has not been named.
(118228) 1996 TQ66 (provisional designation 1996 TQ66) is a resonant trans-Neptunian object of the plutino population in the Kuiper belt, located in the outermost region of the Solar System. It was discovered on 8 October 1996, by American astronomers Jun Chen, David Jewitt, Chad Trujillo, and Jane Luu, using the UH88 telescope at the Mauna Kea Observatories, Hawaii. The very red object measures approximately 185 kilometers (110 miles) in diameter. As of 2021, it has not been named.
(523731) 2014 OK394 (provisional designation 1995 SN55) is a trans-Neptunian object that orbits in the outer Solar System beyond the orbit of Neptune. First observed as 1995 SN55 by Spacewatch on 20 September 1995, it was a lost minor planet with an insufficiently defined orbit with only 36 days of observations. On 8 October 2010, it was rediscovered by the Pan-STARRS 1 survey and later announced as 2014 OK394 in July 2016. It was not until November 2020 when amateur astronomers S. Deen and K. Ly identified 2014 OK394 and 1995 SN55 as the same object. This identification was confirmed and announced by the Minor Planet Center in January 2021.
(82075) 2000 YW134 (provisional designation 2000 YW134) is a resonant trans-Neptunian object and binary system, located in the outermost region of the Solar System. It was discovered on 26 December 2000, by astronomers with the Spacewatch survey at Kitt Peak Observatory near Tucson, Arizona. The reddish object stays in a rare 3:8 resonance with Neptune. A smaller companion was discovered by the Hubble Space Telescope in October 2002. As of 2021, neither the primary body nor its satellite have been named.
(523639) 2010 RE64 (provisional designation 2010 RE64) is a trans-Neptunian object in the scattered disc located in the outermost region of the Solar System, approximately 570 kilometers (350 miles) in diameter. It was discovered on 11 July 2010 by the Pan-STARRS-1 survey at the Haleakala Observatory, Hawaii, in the United States.
(101869) 1999 MM is a sub-kilometer asteroid on an eccentric orbit, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. It was discovered on 20 June 1999, by the Lowell Observatory Near-Earth-Object Search (LONEOS) at its U.S. Anderson Mesa Station in Flagstaff, Arizona. The first observation was made by Catalina Sky Survey just 8 days before its official discovery.
(523671) 2013 FZ27 (provisional designation 2013 FZ27) is a trans-Neptunian object located in the Kuiper belt in the outermost region of the Solar System, approximately 570 kilometers (350 miles) in diameter. It was discovered on 16 March 2013, by American astronomers Scott Sheppard and Chad Trujillo at the CTIO in Chile. Numbered in 2018, this minor planet has not been named.
(78799) 2002 XW93, provisional designation 2002 XW93, is a trans-Neptunian object and centaur from the outer Solar System, approximately 500–600 kilometers (300–400 mi) in diameter. It was discovered on 10 December 2002, by astronomers at the Palomar Observatory in California.
(585310) 2017 YZ1, provisional designation: 2017 YZ1, is a sub-kilometer asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 250 meters (800 feet) in diameter. It was first observed on 20 December 2017, by astronomers with the Mount Lemmon Survey at Mount Lemmon Observatory near Tucson, Arizona, in the United States. On 29 January 2018, it passed Earth at 125 lunar distances.
(501581) 2014 OB394, provisional designation 2014 OB394, is a trans-Neptunian object from the outermost region of the Solar System, approximately 260 kilometers (160 miles) in diameter. It was discovered on 25 August 2012, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States. The weak dwarf planet candidate was numbered in 2017 and remains without a name.
(501546) 2014 JJ80, prov. designation:2014 JJ80, is a trans-Neptunian object from the outermost region of the Solar System. It was discovered on 9 July 2013, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States. It is a dwarf planet candidate, as it measures approximately 350 kilometers (220 miles) in diameter.
(523706) 2014 HF200 (provisional designation 2014 HF200) is a trans-Neptunian object on an eccentric orbit from the scattered disc, located in the outermost region of the Solar System. It was discovered on 20 May 2012, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States. The dwarf planet candidate measures approximately 300 kilometers (190 miles) in diameter.
(523683) 2014 CP23 (provisional designation 2014 CP23) is a trans-Neptunian object from the scattered disc located in the outermost region of the Solar System It was discovered on 29 October 2011, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States. The dwarf planet candidate measures approximately 267 kilometers (170 miles) in diameter.
(495603) 2015 AM281 (provisional designation 2015 AM281) is a resonant trans-Neptunian object in the outermost region of the Solar System, guesstimated at approximately 470 kilometers (290 miles) in diameter. It was discovered on 13 March 2010, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States.
(505624) 2014 GU53 (provisional designation 2014 GU53) is a trans-Neptunian object and cubewano from the Kuiper belt, located in the outermost region of the Solar System. It was discovered on 8 April 2014, by astronomers with the Pan-STARRS survey at Haleakala Observatory, Hawaii, United States. The classical Kuiper belt object belongs to the hot population and is a dwarf planet candidate, as it measures approximately 330 kilometers (210 miles) in diameter.
2022 UQ1 was a minor planet provisional designation that was mistakenly given to the Lucy mission's Centaur upper stage booster during its Earth gravity assist flyby in October 2022. The object passed about 9,100 km (5,700 mi) from the center of Earth (or an altitude of 2,700 km (1,700 mi) above the surface of Earth) during its closest approach on 16 October 2022.