532037 Chiminigagua
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.
 Chiminigagua (center) and its moon (bottom left), imaged by the Hubble Space Telescope on 15 January 2018 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | |
| Discovery site | Cerro Tololo Obs. (DECam) |
| Discovery date | 17 March 2013 |
| Designations | |
| (532037) Chiminigagua | |
| Pronunciation | /ˌʃɪmɪniˈɡɑːɡwə/ or /ˌtʃɪ-/ (with the PASTA vowel) |
Named after | Chiminigagua |
| 2013 FY27 | |
| Orbital characteristics (barycentric)[5] | |
| Epoch 25 February 2023 (JD 2460000.5) | |
| Uncertainty parameter 3[1] or 4[3] | |
| Observation arc | 13.94 yr (5,093 d) |
| Earliest precovery date | 15 March 2011 |
| Aphelion | 82.000 AU |
| Perihelion | 35.572 AU |
| 58.786 AU | |
| Eccentricity | 0.3949 |
| 450.43 yr (164,520 d) | |
| 216.561° | |
| 0° 0m 7.878s /day | |
| Inclination | 33.121° |
| 187.053° | |
| ≈ 31 October 2202[6] ±10 days[3] | |
| 139.207° | |
| Known satellites | 1[4] |
| Physical characteristics[4] | |
| 742+78 −83 km[a] | |
| 0.170+0.045 −0.030[4] | |
| Temperature | 22 K (perihelion) to 16 K (aphelion)[4]: 1 |
| |
| 22.5[7] | |
| 3.15±0.03[4] | |
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.
History
[edit]Discovery
[edit]Chiminigagua was discovered by Scott Sheppard and Chad Trujillo on 17 March 2013,[1] during a search for distant trans-Neptunian objects (TNOs).[8][4] Their search was performed using the 4.0-meter Víctor M. Blanco Telescope's Dark Energy Camera (DECam) at Cerro Tololo Observatory in Chile,[1] which repeatedly imaged large portions of the sky to reveal TNOs as slow-moving objects.[9]: 3 Sheppard and Trujillo had been searching for TNOs using other telescopes since 2007, but they switched to primarily using DECam when it became operational in 2012.[9]: 3
From May 2013 to March 2014, Sheppard and Trujillo reobserved Chiminigagua using DECam and the 6.5-meter Magellan–Baade Telescope in Las Campanas Observatory, Chile.[2] The Minor Planet Center announced the discovery of Chiminigagua on 31 March 2014 and gave it the minor planet provisional designation 2013 FY27.[2]
Before Chiminigagua, Sheppard and Trujillo had discovered several large TNOs with DECam—namely, the sednoid 2012 VP113 and the scattered disc object 2013 FZ27, which were announced along with Chiminigagua within a week of one another in late March to early April 2014.[8][10] When Chiminigagua was discovered, it was nearly at its farthest point from the Sun (aphelion) in its orbit.[8][4] This made Chiminigagua appear dim with an apparent magnitude of 22 from Earth.[8] Because of its faintness, Chiminigagua likely evaded discovery by earlier, less sensitive TNO searches.[8] Chiminigagua has been identified in precovery observations by the Pan-STARRS survey from March 2011 to February 2013.[1]
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Naming and numbering
[edit]The object is named after Chiminigagua,[b] a universally good god that represented the only light that existed when it was night time.[12] She is the creator god of the Muisca (Chibcha) people that inhabit the Andes mountains in the central part of Colombia.[13]: 11 The naming of this object was announced by the International Astronomical Union's Working Group for Small Body Nomenclature (WGSBN) on 11 August 2025.[13]: 11 The name follows the WGSBN's recommended naming theme of mythological creation figures for trans-Neptunian objects, which includes scattered disc objects like Chiminigagua.[14]: 8
Before Chiminigagua was officially named, it was known by its provisional designation 2013 FY27,[1][4] which indicates the year and half-month of the object's discovery date.[15] The Minor Planet Center gave it the minor planet catalog number 532037 on 18 May 2019.[16]
Orbit
[edit]
Chiminigagua is a trans-Neptunian object (TNO) orbiting the Sun at a semi-major axis or average distance of 58.9 astronomical units (AU).[5][c] It follows a highly tilted and elliptical orbit with an eccentricity of 0.39 and inclination of 33.1° with respect to the ecliptic.[5][4]: 1 During its 450-year orbital period, Chiminigagua comes within 35.6 AU from the Sun at perihelion and up to 82.0 AU at aphelion.[5] This large variation in distance from the Sun means Chiminigagua experiences large variations in surface temperature over the course of its orbit: at perihelion Chiminigagua would be 22 K (−251.2 °C; −420.1 °F), whereas at aphelion it would be 16 K (−257.1 °C; −430.9 °F).[4]: 1
Chiminigagua belongs to the scattered disc, which is a population of TNOs that have distant, inclined, and eccentric orbits that come close to Neptune at perihelion.[8] The scattered disc population, which includes the dwarf planets Eris and Gonggong, are strongly influenced by Neptune's gravitational perturbations and consequently experience gravitational scattering.[18]: 52
Chiminigagua passed aphelion in March–April 1978[19] and is now moving closer to the Sun until it will reach perihelion between October and November 2202.[6][d] Chiminigagua previously passed perihelion in April–May 1752.[20] Chiminigagua was 80.5 AU away from the Sun when it was discovered,[9]: 15 and it has since moved a few AU closer.[21] There are over 20 known TNOs that are located farther away from the Sun than Chiminigagua as of 2025[update].[22]
Physical characteristics
[edit]Size
[edit]Chiminigagua has a diameter of about 742 km (461 mi) (full range 660 to 820 km or 410 to 510 mi when including uncertainties), according to Atacama Large Millimeter Array measurements of its thermal emission.[4]: 7 Chiminigagua has an absolute magnitude of 3.15±0.03 in visible light,[4]: 4 which makes it the ninth intrinsically brightest TNO known as of 2025[update].[23] Chiminigagua is large and bright enough that some astronomers and planetary scientists, including Scott Sheppard, Emily Lakdawalla, and Michael E. Brown, have called it a likely dwarf planet.[8][24][25]
Among TNO researchers, Chiminigagua is better known as belonging to the proposed class of "mid-sized" TNOs[26] between 400 and 1,000 km (250 and 620 mi) in diameter, which are believed to represent the transition between small, low-density TNOs and large, high-density dwarf planets.[27][4]: 1 Planetary scientists have hypothesized that mid-sized TNOs should have highly porous and unheated interiors, because TNOs in this size range (namely 55637 Uni and 229762 Gǃkúnǁʼhòmdímà) have been found to have low densities around 1 g/cm3.[27][26][28] The mass and density of Chiminigagua is unknown, however, because the orbit of its moon has not been determined yet.[26][28] Hubble Space Telescope observations in December 2025 and January 2026 will be able to determine Chiminigagua's mass and density, which will verify the aforementioned hypothesis on the interiors of mid-sized TNOs.[28]
Surface
[edit]
Observations of Chiminigagua in different light filters show that it has a moderately red color, which is common among mid-sized TNOs.[4]: 3 The moderately red color of Chiminigagua suggests it has an old, ice-poor surface that has been dulled by cosmic rays and micrometeoroid bombardment, in contrast to the fresh, icy surfaces of larger dwarf planets like Pluto.[4]: 1, 3 Chiminigagua's brightness and diameter indicates it has a moderate geometric albedo of 0.170+0.045
−0.030,[4] which is on the high end for mid-sized TNOs with moderately red colors.[4]: 8, 10
Rotation
[edit]The rotation period of Chiminigagua is unknown.[4] Observations of Chiminigagua's brightness over time in March and May 2016 showed no obvious variability beyond 0.06±0.02 magnitudes over hours and days.[4]: 3 The lack of brightness variation suggests that Chiminigagua has either a very long rotation period, an approximately spheroidal shape with no significant albedo variation, or a rotation axis pointing towards Earth.[4]: 3, 11
Satellite
[edit] Timelapse animation of Chiminigagua's moon (yellow arrow) orbiting back and forth, as seen by the Hubble Space Telescope from January to July 2018 | |
| Discovery[4] | |
|---|---|
| Discovered by | Scott S. Sheppard[29] |
| Discovery site | Hubble Space Telescope |
| Discovery date | 15 January 2018 |
| Orbital characteristics[4] | |
| >9800±40 km | |
| ≈19 d (for assumed density of 1.6 g/cm3)[30] | |
| Satellite of | 532037 Chiminigagua |
| Physical characteristics | |
| 186+25 −26 km (assuming same albedo as Chiminigagua)[4] | |
| Albedo | 0.170+0.045 −0.030 (assumed)[4] |
| 25.5[7] | |
| 6.15[e] | |
Chiminigagua has one known moon. As of 2026, it has no official designation or name.[3]
Discovery
[edit]The moon was discovered by Scott Sheppard using the Hubble Space Telescope's Wide Field Camera 3 on 15 January 2018, whose high-resolution images revealed it as a faint dot next to Chiminigagua.[4]: 9
Sheppard reported the moon to the International Astronomical Union,[4]: 9 which announced the discovery on 10 August 2018 through the Central Bureau for Astronomical Telegrams.[29]
Observations and orbit
[edit]Although Chiminigagua's moon has been observed multiple times by the Hubble Space Telescope from January to July 2018, the details of its orbit are unknown.[7][28]
These Hubble observations from 2018 showed that the moon orbits relatively close to Chiminigagua, at least 9,800 km (6,100 mi) away (0.17 arcseconds in angular separation)[4]: 9 but no farther than 0.25 arcseconds.[26]
The orbit of Chiminigagua's moon is oriented edge-on from Earth's perspective, which means that the moon can pass in front of or behind Chiminigagua and thus evade detection.[26][28]
The Hubble Space Telescope observed Chiminigagua and its moon in December 2025 and January 2026, which should be able to determine the moon's orbit.[28]
Physical characteristics
[edit]Size
[edit]The moon is 3.0±0.2 magnitudes fainter than Chiminigagua, which suggests it has a diameter between 160 and 211 km (99 and 131 mi) (or about 1/4 of Chiminigagua's diameter) under the assumption that the moon's albedo is the same as Chiminigagua's.[30][4]: 9
Origin
[edit]Compared to other mid-sized TNOs with moons, the secondary is rather small compared to the primary of the Chiminigagua system.[4]: 10
The relatively small size and close orbit of the moon suggests it formed from an impact on Chiminigagua, similar to the small moons of the larger dwarf planets.[4]: 10
See also
[edit]Notes
[edit]- ^ 742+78
−83 km is the estimated diameter of Chiminigagua by itself, if it and its moon have equal albedos (equally reflective surfaces).[4] It is important to take the moon's albedo into account because the moon slightly adds to Chiminigagua's total brightness, which makes the object appear slightly brighter and bigger than it actually is (e.g. resulting in an "effective" diameter of 765+80
−85 km).[4] - ^ In the Chibcha language, the Ch was apparently pronounced something like an English sh.[11][better source needed]
- ^ These orbital elements are expressed in terms of the Solar System Barycenter (SSB) as the frame of reference.[5] Due to planetary perturbations, the Sun revolves around the SSB at non-negligible distances, so heliocentric-frame orbital elements and distances can vary in short timescales as shown in JPL-Horizons.[17]
- ^ The uncertainty in Chiminigagua's time of perihelion passage is approximately 10.2 days (1-sigma) or 30.6 days (3-sigma; three times the 1-sigma uncertainty).[3]
- ^ Given the primary's absolute magnitude of H = 3.15 and a magnitude difference of Δm = 3.00 between the primary and moon, the sum of those magnitudes is the moon's absolute magnitude, 6.15.[4][7]
References
[edit]- ^ a b c d e f g "(532037) Chiminigagua = 2013 FY27". Minor Planet Center. Retrieved 15 August 2025.
- ^ a b c "MPEC 2014-F82 : 2013 FY27". IAU Minor Planet Center. 31 March 2014. Retrieved 29 March 2018. (K13F27Y)
- ^ a b c d e "JPL Small-Body Database Lookup: 532037 Chiminigagua (2013 FY27)" (2025-02-22 last obs.). Jet Propulsion Laboratory. Retrieved 15 August 2025.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai Sheppard, Scott; Fernandez, Yanga; Moullet, Arielle (6 September 2018). "The Albedos, Sizes, Colors and Satellites of Dwarf Planets Compared with Newly Measured Dwarf Planet 2013 FY27". The Astronomical Journal. 156 (6): 270. arXiv:1809.02184. Bibcode:2018AJ....156..270S. doi:10.3847/1538-3881/aae92a. S2CID 119522310.
- ^ a b c d e "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) at epoch JD 2460000.5". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 15 August 2025. Solution using the Solar System Barycenter. Ephemeris Type: Elements and Center: @0)
- ^ a b "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) from 2202-Oct-20 to 2202-Nov-10". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 15 August 2025. (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 1-sigma from JPL Small-Body Database.)
- ^ a b c d Grundy, Will (22 August 2025). "Chiminigagua (532037 2013 FY27)". Lowell Observatory. Retrieved 15 September 2025.
- ^ a b c d e f g Lakdawalla, Emily (2 April 2014). "More excitement in the outermost solar system: 2013 FY27, a new dwarf planet". The Planetary Society. Archived from the original on 4 August 2020. Retrieved 18 January 2017.
- ^ a b c Sheppard, Scott S.; Trujillo, Chadwick (December 2016). "New Extreme Trans-Neptunian Objects: Toward a Super-Earth in the Outer Solar System". The Astronomical Journal. 152 (6): 221. arXiv:1608.08772. Bibcode:2016AJ....152..221S. doi:10.3847/1538-3881/152/6/221. S2CID 119187392. 221.
- ^ Winter, Lisa (3 April 2014). "Two New Dwarf Planets Discovered in Outer Solar System". IFLScience. Archived from the original on 2 July 2022. Retrieved 15 August 2025.
- ^ Muysc cubun Project
- ^ (in Spanish) Chiminigagua - Pueblos Originarios
- ^ a b "WGSBN Bulletin 5, #19" (PDF). WGSBN Bulletin. 5 (19). International Astronomical Union: 11. 11 August 2025. Retrieved 11 August 2025.
- ^ "Rules and Guidelines for Naming Non-Cometary Small Solar-System Bodies" (PDF). IAU Working Group for Small Bodies Nomenclature. 20 December 2021. Retrieved 15 August 2025.
- ^ "New- And Old-Style Minor Planet Designations". Minor Planet Center. Retrieved 15 August 2025.
- ^ "M.P.C. 47762" (PDF). Minor Planet Circulars (114692). Minor Planet Center: 2256. 18 May 2019. Retrieved 11 August 2025.
- ^ "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) at epochs JD 2450000.5–2460000.5". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 15 August 2025. Solution using the Sun. Ephemeris Type: Elements and Center: @sun)
- ^ Gladman, Brett; Marsden, Brian G.; VanLaerhoven, Christa (2008). "Nomenclature in the Outer Solar System" (PDF). The Solar System Beyond Neptune. University of Arizona Press. pp. 43–57. arXiv:astro-ph/0702538. Bibcode:2008ssbn.book...43G. ISBN 9780816527557. S2CID 14469199. Archived from the original (PDF) on 1 August 2023.
- ^ "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) from 1978-Mar-20 to 1978-Apr-10". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 16 August 2025. (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 1-sigma from JPL Small-Body Database.)
- ^ "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) from 1752-Apr-10 to 1752-May-20". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 16 August 2025. (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 1-sigma from JPL Small-Body Database.)
- ^ "JPL Horizons On-Line Ephemeris for 532037 Chiminigagua (2013 FY27) from 2013-Mar-17 to 2026-Jan-01". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 16 August 2025. (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 1-sigma from JPL Small-Body Database.)
- ^ "AstDyS-2, Asteroids – Dynamic Site". Asteroids Dynamic Site. Retrieved 15 August 2025.
Objects with distance from Sun over 79 AU
- ^ "MPC Database Search: H < 3.8 and a > 20 AU". Minor Planet Center. Archived from the original on 16 August 2025. Retrieved 16 August 2025.
22 trans-Neptunian objects brighter than H = 3.8
- ^ Scott Sheppard (7 April 2017). "A Satellite Search of a Newly Discovered Dwarf Planet – HST Proposal 15248". Retrieved 9 September 2018.
- ^ Scott Sheppard (21 March 2018). "The Orbit of the Newly Discovered Satellite around the Dwarf Planet 2013 FY27 - HST Proposal 15460". Retrieved 9 September 2018.
- ^ a b c d e Nelsen, Maia; Ragozzine, Darin; Giforos, William; Proudfoot, Benjamin; Sheppard, Scott S.; Grundy, William (December 2022). Constraints on the Orbit of the Moon of Mid-Size TNO 2013 FY27. AAS Division of Planetary Science meeting #54. Vol. 54. Bibcode:2022DPS....5441006N. 410.06.
- ^ a b Grundy, W. M.; Noll, K. S.; Buie, M. W.; Benecchi, S. D.; Ragozzine, D.; Roe, H. G. (December 2019). "The Mutual Orbit, Mass, and Density of Transneptunian Binary Gǃkúnǁʼhòmdímà ((229762) 2007 UK126)" (PDF). Icarus. 334: 30–38. Bibcode:2019Icar..334...30G. doi:10.1016/j.icarus.2018.12.037. S2CID 126574999.
- ^ a b c d e f Ragozzine, Darin (August 2025). "Probing the TNO Density Transition with Mid-Size 2013 FY27". Mikulski Archive for Space Telescopes. Space Telescope Science Institute: HST Proposal 18133. Bibcode:2025hst..prop18133R. Cycle 33. Retrieved 16 August 2025.
- ^ a b Green, Daniel W. E. (10 August 2018). "CBET 4537: 2013 FY27". Central Bureau Electronic Telegram. Central Bureau for Astronomical Telegrams. Bibcode:2018CBET.4537....1S. Retrieved 9 September 2018.
- ^ a b Johnston, Wm. Robert (27 May 2019). "(532037) 2013 FY27". Johnston's Archive. Retrieved 3 January 2023.
External links
[edit]
- Gaggle of dwarf planets found by Dark Energy Camera (Aviva Rutkin: 2 April 2014)
- 532037 Chiminigagua at AstDyS-2, Asteroids—Dynamic Site
- 532037 Chiminigagua at the JPL Small-Body Database
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