(95626) 2002 GZ32

Elongated centaur September 2025 yes (95626) 2002 GZ 32 #C7FF8F 2002 GZ32 Hubble 2008.png 2002 GZ 32 imaged by the Hubble Space Telescope on 26 February 2008 13 April 2002 Mauna Kea Obs.The Minor Planet Center lists "Mauna Kea" as the discoverer without listing specific people. Mauna Kea Obs. (95626) 2002 GZ 32 centaurdistant 5 May 2025 (JD 2460800.5) 0 30.33 yr 29 March 1995 27.991 AU 18.003 AU 10 August 2019 22.997 AU 0.2171 110.28 yr (40,281 days) 18.718° 0.0089372 ms / day 15.046° 107.295° 155.376° 7.987 AU 1.400 AU 2.347 AU 0 366 x 306 x 120 km 218 12 km (area equivalent) 5.80 0.03 h 0.043 0.007 BR (TNO color class)484 B−V 0.63 0.05484 V−R 0.46 0.03484 V−I 0.92 0.05484 ~20 7.39 0.066063 (95626) 2002 GZ 32 is a centaur orbiting the Sun between Saturn and Neptune in the outer Solar System. It is one of the largest known centaurs, having a highly elongated shape that spans 366 km mi across its longest width to 120 km mi across its shortest. The object was discovered on 13 April 2002 by astronomers at Mauna Kea Observatory in Hawaiʻi. Due to 2002 GZ 32's highly elongated shape, its apparent brightness oscillates as it rotates every 5.8 hours. 2002 GZ 32 has a dark gray surface that potentially contains water ice.6063 It was the third centaur whose stellar occultation has been simultaneously observed by multiple people, after 10199 Chariklo and 2060 Chiron. History Discovery thumb|left|2002 GZ 32 imaged by the Canada–France–Hawaii Telescope on 13 April 2002 2002 GZ 32 was discovered on 13 April 2002 by astronomers at Mauna Kea Observatory in Hawaiʻi. The observatory's 8.2-meter Subaru Telescope and University of Hawaiʻi 2.24-meter telescope were used for the discovery of 2002 GZ 32.June 2026 Astronomers involved in the discovery included Jana Pittichová, S. Ash, Karen Meech, James Bauer, David C. Jewitt, Richard Wainscoat, Daisuke Kinoshita, Junichi Watanabe, Tetsuharu Fuse, Marc Buie, Scott Sheppard, and N. Yamamoto. The discovery of this object was announced by the Minor Planet Center (MPC) on 18 May 2002, after the object was reobserved in the same month. In 2007, astronomer Andrew Lowe reported precovery observations of 2002 GZ 32 in Palomar Observatory's Digitized Sky Survey images from March 1995 and May 1996, which helped improve calculations of the object's orbit. These precovery observations remain as the earliest known detections of 2002 GZ 32. Number and name This object has the minor planet provisional designation 2002 GZ 32, which was given by the MPC in the discovery announcement. The provisional designation indicates the year and half-month of the object's discovery date. 2002 GZ 32 received its permanent minor planet catalog number of 95626 from the MPC on 28 October 2004. 2002 GZ 32 does not have a proper name; more than ten years has passed since the object was numbered, so the discoverers no longer have an exclusive privilege for naming this object.6 According to naming guidelines by the International Astronomical Union's Working Group for Small Bodies Nomenclature, 2002 GZ 32 should be named after a mythological centaur because it orbits between Jupiter and Neptune.8 Orbit thumb|left|Diagram showing the orbit of 2002 GZ 32 with the outer planets 2002 GZ 32 orbits the Sun between Saturn and Neptune with an average orbital distance of 23 astronomical units (AU) and an orbital period of 110 years. It follows an elliptical orbit that crosses paths with Uranus, bringing the object within 18 AU from the Sun at perihelion to as far as 28 AU at aphelion. The orbit of 2002 GZ 32 is inclined by roughly 15° with respect to the ecliptic or the orbital plane of the planets. 2002 GZ 32 is classified as a centaur, a type of small Solar System body generallyThere is no universally agreed definition of a centaur, as different researchers have argued for using different criteria (see Centaur (small Solar System body)#Discrepant criteria). Regardless, centaurs are broadly cited as orbiting between Jupiter and Neptune. defined as orbiting between Jupiter and Neptune.6062 Centaurs are believed to be primitive progenitors of short-period comets, originating from the scattered disc beyond Neptune.6062 Physical characteristics Size, shape, and rotation thumb|upright=1.5|Comparison of sizes, albedos, and colors of various large centaurs with measured diameters. 2002 GZ 32 is at the right in the top row.|alt=Infographic showing a comparison of sizes, albedo, and colors of various large centaurs 2002 GZ 32 is a highly elongated object with estimated ellipsoid dimensions of 366 × 306 × 120 km mi. Its size may be represented with an area equivalent diameter of 218 km mi,6071 which would make it one of the largest known centaurs after 10199 Chariklo and 2060 Chiron.6063 The shape of 2002 GZ 32 was revealed to astronomers when it occulted or passed in front of a star on 20 May 2017. This occultation event was simultaneously observed by 6 out of 29 different telescopes across Europe, which allowed astronomers to map out the silhouette of 2002 GZ 32's shape for the first time. 2002 GZ 32 was the third centaur whose stellar occultation has been simultaneously observed by multiple people, after 10199 Chariklo and 2060 Chiron.Santos-Sanz et al. (2021) say that 2002 GZ 32 was the fourth centaur with multichord occultation observations (simultaneously observed by multiple people), citing a study of Bienor's 2019 multichord occultation that was not yet published at the time. This Bienor multichord occultation study was later published by Fernández-Valenzuela et al. in 2023. For the purpose of this article, we will consider 2002 GZ 32 as the third centaur with multichord observations, according to the time order of the observation and publication date. Observations from 2007 and 2017 showed that 2002 GZ 32's apparent brightness oscillates sinusoidally with a double-peak period of 5.8 hours.8326065 The rotation of 2002 GZ 32's elongated body causes these brightness variations, so the observed double-peak period is equal to 2002 GZ 32's rotation period.6065 The minimum degree of elongation suggested by 2002 GZ 32's brightness variations (a/b 1.13 for Δm 0.13 magnitudes) does not match the actual shape seen in the 2017 occultation, which indicates that the object's rotation axis must be tilted with respect to Earth's line of sight.6069 Analysis of the 2017 occultation data suggests that the aspect angle between 2002 GZ 32's rotation axis and Earth's line of sight was most likely 76°.6069 The observed shape and rotation period of 2002 GZ 32 do not match theoretical predictions for a purely self-gravitating body, which means that 2002 GZ 32 is not in hydrostatic equilibrium. This is expected because 2002 GZ 32 is likely too small to be in hydrostatic equilibrium.6069 Surface 2002 GZ 32 is a dark gray object358 whose surface potentially contains water ice.6063 It has a low geometric albedo of about 4%, similar to many other centaurs. Searches for surrounding material Radio telescope observations from 2002 found no signs of carbon monoxide (CO) outgassing from 2002 GZ 32, which places an upper limit CO production rate of 3.8 28 molecules per second.404 Observations of the 20 May 2017 stellar occultation by 2002 GZ 32 showed no dense rings or debris surrounding the object, although thin rings with radial widths narrower than about a kilometer have not been ruled out.6071 See also List of centaurs (small Solar System bodies) 95626 54598 Bienor – a large and highly elongated centaur similar to 2002 GZ 32 Notes References 30em 2025-07-26 last obs. JPL Small-Body Database Lookup: 95626 (2002 GZ32) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=20095626 Jet Propulsion Laboratory 2025-09-08 (95626) = 2002 GZ32 https://www.minorplanetcenter.net/db_search/show_object?object_id=95626 Minor Planet Center 2025-09-08 New- And Old-Style Minor Planet Designations https://www.minorplanetcenter.net/iau/info/DesDoc.html Minor Planet Center 2025-09-08 Rules and Guidelines for Naming Non-Cometary Small Solar-System Bodies https://www.wgsbn-iau.org/documentation/NamesAndCitations.pdf IAU Working Group for Small Bodies Nomenclature 2025-02-22 2025-09-08 AstDys (95626) 2002GZ32 Ephemerides https://newton.spacedys.com/astdys/index.php?pc=1.1.3.0&n=95626 Asteroids - Dynamic Site Department of Mathematics, University of Pisa, Italy 2025-09-08 etal J. Pittichova K. J. Meech Karen J. Meech S. Ash J. Bauer D. C. Jewitt David C. Jewitt R. Wainscoat MPEC 2002-K15 : 2002 FY36, 2002 GY32, 2002 GZ32, 2002 GA33, 2002 GB33 https://minorplanetcenter.net/mpec/K02/K02K15.html Minor Planet Electronic Circular Minor Planet Center 2002-05-18 2002-K15 2025-09-08 2002MPEC....K...15P M.P.C. 52955 https://minorplanetcenter.net/iau/ECS/MPCArchive/2004/MPC_20041028.pdf#page=109 Minor Planet Circulars Minor Planet Center 52955 109 2004-10-28 2025-09-08 (95626) 2002 GZ 32 Precovery Images https://andrew-lowe.ca/95626.htm Andrew Lowe Andrew Lowe (astronomer) andrew-lowe.ca 2025-09-08 live https://web.archive.org/web/20250908203259/https://andrew-lowe.ca/95626.htm 2025-09-08 etal S. Fornasier A. Doressoundiram G. P. Tozzi M. A. Barucci H. Boehnhardt C. de Bergh ESO Large Program on physical studies of Trans-Neptunian objects and Centaurs: Final results of the visible spectrophotometric observations Astronomy & Astrophysics July 2004 421 353–363 free 10.1051/0004-6361:20041221 2004A&A...421..353F 54983080 David Jewitt Catherine A. Garland Herve Aussel Deep Search for Carbon Monoxide in Cometary Precursors Using Millimeter Wave Spectroscopy Astronomy & Astrophysics January 2008 135 1 400–407 free 10.1088/0004-6256/135/1/400 2008AJ....135..400J 121477792 etal E. Dotto D. Perna M. A. Barucci A. Rossi C. de Bergh A. Doressoundiram Rotational properties of Centaurs and Trans-Neptunian Objects. Lightcurves and densities Astronomy & Astrophysics November 2008 490 2 829–833 free 10.1051/0004-6361:200809615 2008A&A...490..829D 54705887 Irina N. Belskaya Maria A. Barucci Marcello Fulchignoni M. Lazzarin Updated taxonomy of trans-neptunian objects and centaurs: Influence of albedo Icarus April 2015 250 482–491 10.1016/j.icarus.2014.12.004 2015Icar..250..482B etal P. Santos-Sanz J. L. Ortiz B. Sicardy G. Benedetti-Rossi N. Morales E. Fernández-Valenzuela The 2017 May 20 stellar occultation by the elongated centaur (95626) 2002 GZ 32 Monthly Notices of the Royal Astronomical Society March 2021 501 4 6062–6075 free 10.1093/mnras/staa3881 2012.06621 2021MNRAS.501.6062S 229156443 A "magnifying glass" look at one of the largest known centaurs https://archive.iaa.csic.es/en/news/magnifying-glass-look-one-largest-known-centaurs Instituto de Astrofísica de Andalucía en 2021-02-03 2025-09-08 live https://web.archive.org/web/20250807153315/https://archive.iaa.csic.es/en/news/magnifying-glass-look-one-largest-known-centaurs 2025-08-07 etal E. Fernández-Valenzuela N. Morales M. Vara-Lubiano J. L. Ortiz G. Benedetti-Rossi B. Sicardy The multichord stellar occultation by the centaur Bienor on January 11, 2019 Astronomy & Astrophysics January 2023 669 A112 free 10.1051/0004-6361/202243214 2211.06931 2023A&A...669A.112F 253510891 External links 95626 95179 Berkó 95626 (95626) 2002 GZ 32 98943 Torifune 095626 095626 20020413 095626 095626