Quaoar - Wikiparency

# Quaoar  **Microsim — three.js (Wikitube framework):** *Quaoar in the Solar System explorer* <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/solar/Solar_System.html?obj=Quaoar&embed=1" data-title="Quaoar in the Solar System explorer"></div> *The Solar System explorer locked on this article's state (`?obj=Quaoar`); every object and population of the [[PORTAL_Solar_System|Solar System portal]] has its own state in the same scene.*  *Try: set the speed to 100 years/s and follow Quaoar round its nearly circular path, which keeps it at almost the same distance from the Sun all the way round, and compare it with the stretched orbits of Pluto and Neptune's other neighbours; drag to an edge-on view to see its modest 8° tilt; press o to hide the orbits and watch the bodies alone.* **Quaoar** (minor-planet number 50000) is a ringed [[Dwarf_planet|dwarf planet]] and [[Trans-Neptunian_object|trans-Neptunian object]] of the [[Kuiper_belt|Kuiper belt]], about 1,100 km across, roughly half the diameter of [[Pluto]].[^margoti2026][^fs-pluto] Chad Trujillo and Michael Brown discovered it at Palomar Observatory on 4 June 2002, and at the time it was the largest body found in the Solar System since Pluto.[^mpec2002][^hubble2002] It is named after the creator force of the Tongva people of the Los Angeles Basin.[^caltech2002] Its dark, moderately red surface carries crystalline water ice, tholins, ethane and traces of methane.[^jewitt2004][^emery2024] Quaoar has two narrow rings that lie well outside its Roche limit, the distance within which rings are expected to survive, which challenges standard ideas of how rings and moons form.[^morgado2023][^pereira2023] It has one confirmed moon, Weywot, and a possible second, smaller moon detected in a 2025 occultation.[^iauc8812][^nolthenius2025] The explorer at the top of this page is locked on Quaoar: it draws the orbit from JPL's Small-Body Database, nearly circular with an eccentricity of 0.035 at about 43 [[Astronomical_unit|AU]]; the rings and moons are too small to show at this scale.[^sbdb] ## History ### Discovery Quaoar was found as part of the Caltech Wide Area Sky Survey, a search for the brightest Kuiper belt objects with the 1.22-metre Samuel Oschin telescope at Palomar Observatory in California.[^trujillo2003] The images were taken on 4 June 2002; Trujillo noticed the object the next day, a faint point of magnitude 18.6 creeping among the stars of Ophiuchus, bright enough for its distance to suggest a body of Pluto-like size.[^trujillo-faq][^mpec2002] To fix the orbit, Brown and Trujillo searched archives and found the object on survey images from 1996 and 2000–2002 and on two plates taken in May 1983 by Charles Kowal during his own search for a planet beyond Neptune; the earliest image now known is a Palomar Sky Survey plate of 25 May 1954.[^mpec2002][^mpc] Brown wanted a size measurement before announcing the find, and obtained Hubble Space Telescope time for it directly rather than through the usual peer review; he also used time already scheduled at the Keck telescopes in Hawaii to take Quaoar's spectrum.[^brown2010][^hst9678] The discovery was announced by the Minor Planet Center on 7 October 2002, the same day Trujillo and Brown presented their results at the meeting of the American Astronomical Society's Division for Planetary Sciences in Birmingham, Alabama, as the largest Kuiper belt object yet found, larger than the previous record holders.[^mpec2002][^hubble2002] Brown later counted the discovery among those that led to Pluto's reclassification.[^brown2010] On 20 November 2002 the object received the deliberately round minor-planet number 50000, marking its size, as the large object Varuna had earlier received 20000.[^mpc47066] ### Name and symbol Until it was named, the team called the object "Object X", after the long-sought Planet X.[^brown2010] Under IAU rules, non-resonant Kuiper belt objects take the names of creation deities, and the discoverers looked to the mythology of the Tongva, the Indigenous people of the Los Angeles Basin, where Caltech is based. They chose Kwawar, the creation force that sings and dances the other gods into existence, beginning with Weywot, the sky father.[^caltech2002][^trujillo-faq] After contacting the Tongva and the tribal historian Marc Acuña, who approved the choice, they adopted the tribe's preferred spelling, Qua-o-ar, without the hyphens.[^trujillo-faq][^brown2010] The name was announced with the discovery in October, before the object was numbered, which Brian Marsden of the Minor Planet Center later described as a breach of protocol; it was nonetheless approved and published in November 2002.[^mpec2004s73][^mpc47066] A symbol for Quaoar, designed by Denis Moskowitz, combines the letter Q with a canoe in a style recalling Tongva rock art; it was added to Unicode in 2022 and is used mainly by astrologers.[^unicode2022] ## Orbit and classification Quaoar orbits the [[Sun]] on one of the most circular paths among large trans-Neptunian objects: its eccentricity of 0.035 keeps it between about 41.6 and 44.7 AU, and it takes roughly 285 years to go round (derived).[^sbdb] At that distance, sunlight needs about six hours to arrive (derived). It passed aphelion late in 1932 and is now slowly approaching perihelion, which it will reach around February 2075.[^horizons] Because the orbit stays well outside [[Neptune]]'s, the planet does not disturb it strongly. Quaoar's minimum orbit intersection distance with Neptune is 12.3 AU, and it is not held in any mean-motion [[Resonance|resonance]]; Deep Ecliptic Survey integrations show its perihelion and aphelion distances hardly changing over the next ten million years.[^mpc][^buie] It is therefore a [[Classical_Kuiper_belt_object|classical Kuiper belt object]], or cubewano, in the classifications of both the Minor Planet Center and the Deep Ecliptic Survey.[^buie][^mpec2008] Its inclination of about 8° to the [[Ecliptic|ecliptic]] is higher than those of the dynamically "cold" classical objects, which place it in the "hot" population; such inclinations are thought to have been raised by gravitational scattering as Neptune moved outward in the young Solar System, as in the [[Nice_model|Nice model]].[^delsanti2006][^levison2008] The explorer draws the present osculating orbit from JPL elements; compared with the plutinos, its near-circular shape is plain to see.[^sbdb] ## Physical characteristics ### Size and shape Estimates of Quaoar's size have converged over two decades, as direct imaging and thermal measurements gave way to stellar occultations, in which the shadow of the body is timed as it crosses observers on [[Earth]]. | Year | Diameter (km) | Method | Source | |---|---|---|---| | 2004 | 1,260 | Hubble imaging | Brown and Trujillo[^brown2004] | | 2008 | 844 | thermal (Spitzer) | Stansberry et al.[^stansberry2008] | | 2010 | 890 | thermal and imaging | Fraser and Brown[^fraser2010] | | 2013 | 1,074 | thermal (Herschel) | Fornasier et al.[^fornasier2013] | | 2013 | 1,110 | occultation | Braga-Ribas et al.[^braga2013] | | 2024 | 1,090 | thermal and occultation | Kiss et al.[^kiss2024] | | 2026 | 1,094 | 37 occultations | Margoti et al.[^margoti2026] | The shape is debated. Kiss and colleagues argued in 2024 from the light curve and occultations that Quaoar is an elongated triaxial body, although a slowly rotating body of its size in hydrostatic equilibrium should be a flattened spheroid; they proposed that it once spun faster and kept its shape "frozen in" as tides from Weywot slowed it, as [[Saturn]]'s moon Iapetus has kept an outdated bulge.[^kiss2024][^castillo2007] Margoti and colleagues' analysis of 37 occultations, published in 2026, instead fits an oblate spheroid with equatorial and polar diameters of about 1,132 and 1,022 km, consistent with a Maclaurin spheroid in equilibrium for its 8.84-hour rotation.[^margoti2026][^ortiz2003] ### Mass and density The orbit of Weywot gives Quaoar's mass, about 1.2 × 10²¹ kg, through [[Kepler's_laws_of_planetary_motion|Kepler's third law]].[^proudfoot2025w] Proudfoot and colleagues, modelling nearly 20 years of astrometry, found that Weywot's orbit is measurably non-Keplerian, pulled by Quaoar's flattened [[Gravitational_field|gravity field]], and derived a bulk density of 1.751 g/cm³; the small flattening they measured implies that Quaoar is differentiated into a rocky core and an icy mantle.[^proudfoot2025w] The occultation shape gives a consistent density of 1.76 g/cm³.[^margoti2026] Earlier estimates were much higher, because the diameter was underestimated and the mass overestimated. Fraser and Brown's 2010 study, titled "Quaoar: a rock in the Kuiper belt", suggested a dense body that had lost most of its ice in a giant impact; that picture has been abandoned with the newer, lower [[Density|density]].[^fraser2010][^kiss2024] ### Surface Quaoar is fairly dark, reflecting about 12.5 percent of the visible light that falls on it, and moderately red.[^margoti2026][^jewitt2004] In 2004 Jewitt and Luu detected crystalline [[Water|water]] ice and hints of ammonia hydrate. At Quaoar's surface temperature, below 50 K, ice should form in the amorphous state, and radiation should destroy the crystalline form within about ten million years, so the surface must have been heated to at least 110 K within that time, either by impacts or by internal heat from [[Radioactive_decay|radioactive decay]] that might drive cryovolcanism.[^jewitt2004] Hussmann and colleagues calculated that radiogenic heat alone is probably not enough to keep an ocean of liquid water at the core–mantle boundary today.[^hussmann2006] In 2007 Schaller and Brown found small amounts of methane ice, with ethane; since methane is volatile at Quaoar's temperature, they placed it in an intermediate class between the large bodies that keep volatile ices, such as Pluto, [[Eris_(dwarf_planet)|Eris]] and [[Makemake]], and the smaller ones that have lost them.[^schaller2007] JWST spectra taken in 2022 added carbon dioxide ice, abundant ethane and complex organic material, with possible hydrogen cyanide and carbon monoxide, and small amounts of methane, but no clear sign of ammonia hydrates.[^emery2024] Offsets between Weywot's observed and predicted positions also indicate brightness differences with latitude across the surface; Hubble imaging suggests a brighter equator.[^proudfoot2025w] ### Possible atmosphere With methane on its surface, Quaoar might hold a tenuous atmosphere of the gas, but its gravity is too weak to keep nitrogen or carbon monoxide.[^fraser2013] Stellar occultations have searched for one without success: events analysed in 2013 set an upper limit of about 20 nanobar, one in 2019 lowered it to about 10 nanobar, and the combined 2026 analysis puts it below about 0.65 nanobar at three-sigma confidence.[^braga2013][^arimatsu2019][^margoti2026] ## Satellites ### Weywot Quaoar's confirmed moon, Weywot, formally (50000) Quaoar I, was discovered by Michael Brown and Terry-Ann Suer in Hubble Space Telescope images of 14 February 2006; its name is that of the sky god who, in Tongva tradition, is the son of Quaoar.[^iauc8812][^street2008] It orbits about 13,300 km from Quaoar every 12.43 days, outside both rings, on a nearly circular orbit with an eccentricity below 0.02, inclined a few degrees to Quaoar's equator.[^proudfoot2025w][^proudfoot2025m] Occultations show that it is very dark and about 200 km across.[^fernandez2023] Timings of such occultations also refine its orbit.[^braga2025] ### Possible second moon On 25 June 2025 Richard Nolthenius and Kirk Bender, observing with two telescopes at the Oliver Observing Station of the Monterey Institute for Research in Astronomy, each recorded a 1.23-second disappearance of a star near Quaoar that matched neither Weywot nor the rings. They attributed it to a small moon or a dense ring arc, with a moon more likely.[^nolthenius2025] Proudfoot and colleagues estimated that such a moon would be at least 38 km across, about a hundredth of Weywot's mass, and orbit about 5,700–5,800 km from Quaoar every 3.6 days, between the outer ring and Weywot; at magnitude 28 it would be too faint for any current telescope to image.[^proudfoot2025m] Braga-Ribas and colleagues argued in 2026 that catching a single small moon in this way has a probability of only 0.08 percent, which suggests a belt of several small moons or an arc, like the moons and arcs around the rings of [[Saturn]] and [[Neptune]].[^braga2026] Madeira and colleagues examined the dynamics of the feature and the limits on further satellites.[^madeira2026] ## Rings ### Discovery Occultation campaigns of the European Research Council project Lucky Star, run by teams in France, Spain and Brazil, have systematically searched distant bodies for rings and atmospheres. Occultations observed between 2018 and 2021, with the robotic ATOM telescope of the H.E.S.S. observatory in Namibia, the 10.4-metre Gran Telescopio Canarias, ESA's CHEOPS space telescope and amateur observers in Australia, revealed a ring around Quaoar, now called Q1R; the discovery was announced in February 2023.[^morgado2023][^esa2023] A second ring, Q2R, was found in an occultation on 9 August 2022 observed with the 8.2-metre Gemini North and the Canada–France–Hawaii Telescope, and reported in April 2023.[^pereira2023] Quaoar was the fourth minor body found with rings, after the centaurs Chariklo and Chiron and the dwarf planet [[Haumea]].[^morgado2023] ### Properties The outer ring, Q1R, lies 4,057 km from Quaoar's centre, more than seven Quaoar radii and more than twice the Roche limit; inside the Roche limit [[Tide|tides]] pull apart clumps of material, whereas outside it particles would be expected to gather into a moon within decades.[^morgado2023][^pereira2023] The ring is strongly irregular: its width ranges from about 5 to 300 km and its optical depth from 0.004 to 0.7, and it is most opaque where it is narrowest, recalling the F ring among the [[Rings_of_Saturn|rings of Saturn]] and [[Neptune]]'s ring arcs.[^morgado2023][^pereira2023] Q1R lies close to the 1:3 spin–orbit resonance, where particles orbit once for every three rotations of Quaoar, and to the 6:1 mean-motion resonance with Weywot. Morgado and colleagues suggested that these resonances, together with the very low temperature, which makes collisions between icy particles more elastic and less sticky, keep the ring from accreting.[^morgado2023] The inner ring, Q2R, lies at about 2,520 km, also outside the Roche limit, near the 5:7 spin–orbit resonance; it is uniform, about 10 km wide and very tenuous, with an optical depth of about 0.004.[^pereira2023] | Feature | Distance from Quaoar (km) | Width (km) | Note | |---|---|---|---| | Q2R ring | 2,520 | ≈10 | optical depth ≈0.004[^pereira2023] | | Q1R ring | 4,057 | 5–300 | optical depth 0.004–0.7[^morgado2023][^pereira2023] | | Candidate moon (2025) | ≈5,700–5,800 | ≥38 (diameter) | period ≈3.6 days[^proudfoot2025m] | | Weywot | ≈13,300 | ≈200 (diameter) | period 12.43 days[^proudfoot2025w][^fernandez2023] | ## Exploration No spacecraft has visited Quaoar. In July 2016 the LORRI camera on [[NASA]]'s New Horizons took four images of it from about 14 AU.[^jhuapl2016] McGranaghan and colleagues calculated that a flyby mission using a [[Jupiter]] gravity assist could reach Quaoar in about 13.6 years, for several launch dates between 2026 and 2040, arriving when it is 41–43 AU from the Sun.[^mcgranaghan2011] Quaoar has been studied as a flyby target for the Interstellar Probe concept of the Johns Hopkins Applied Physics Laboratory, because of its possible methane atmosphere and cryovolcanism and its position near the direction in which the Sun moves through the local [[Interstellar_medium|interstellar medium]], and has been suggested for China's proposed Shensuo probes to the edge of the [[Heliosphere|heliosphere]].[^brandt2017][^jones2021] ## Notes Derived numbers are computed from the cited values: the orbital period from the JPL value of about 104,000 days, ≈ 285 years; the light time at 43.2 AU, 43.2 × 499 s ≈ 21,600 s ≈ 6.0 hours; the ratio of Quaoar's diameter to Pluto's, 1,094 / 2,377 ≈ 0.46; and the ratio of Q1R's radius to Quaoar's mean radius, 4,057 / 547 ≈ 7.4. ## References [^sbdb]: JPL Small-Body Database, "50000 Quaoar (2002 LM60)" (orbital elements fetched 2026-09-18). https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=50000 [^horizons]: JPL Solar System Dynamics. "Horizons" ephemerides for 50000 Quaoar, 1932–2075. https://ssd.jpl.nasa.gov/horizons/ [^fs-pluto]: Williams, D. R. "Pluto Fact Sheet". NASA NSSDCA, last updated 11 January 2024. https://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html [^mpc]: Minor Planet Center. "50000 Quaoar (2002 LM60)". https://www.minorplanetcenter.net/db_search/show_object?object_id=50000 [^mpec2002]: Marsden, B. G. (7 October 2002). "MPEC 2002-T34: 2002 LM60". Minor Planet Electronic Circular. https://www.minorplanetcenter.net/mpec/K02/K02T34.html [^mpc47066]: Minor Planet Center (20 November 2002). "M.P.C. 47066". https://minorplanetcenter.net/iau/ECS/MPCArchive/2002/MPC_20021120.pdf [^mpec2004s73]: Marsden, B. G. (28 September 2004). "MPEC 2004-S73: Editorial notice". Minor Planet Electronic Circular. https://minorplanetcenter.net/mpec/K04/K04S73.html [^mpec2008]: Marsden, B. G. (17 July 2008). "MPEC 2008-O05: Distant minor planets". Minor Planet Electronic Circular. https://minorplanetcenter.net/mpec/K08/K08O05.html [^buie]: Buie, M. W. "Orbit fit and astrometric record for 50000". Southwest Research Institute. http://www.boulder.swri.edu/~buie/kbo/astrom/50000.html [^hubble2002]: HubbleSite (7 October 2002). "Hubble spots an icy world far beyond Pluto". News release STScI-2002-17. http://hubblesite.org/newscenter/archive/releases/2002/17/text/ [^caltech2002]: Nadin, E. (7 October 2002). "Caltech scientists find largest object in solar system since Pluto's discovery". Caltech. https://www.caltech.edu/about/news/caltech-scientists-find-largest-object-solar-system-plutos-discovery-618 [^trujillo-faq]: Trujillo, C. A. "Frequently asked questions about Quaoar". http://www.chadtrujillo.com/quaoar/ [^trujillo2003]: Trujillo, C. A.; Brown, M. E. (2003). "The Caltech Wide Area Sky Survey". *Earth, Moon, and Planets* 92: 99–112. https://doi.org/10.1023/B:MOON.0000031929.19729.a1 [^brown2010]: Brown, M. E. (2010). *How I Killed Pluto and Why It Had It Coming*. Spiegel & Grau, pp. 63–85. ISBN 978-0-385-53108-5. [^hst9678]: Brown, M. E. (18 June 2002). "Direct measurement of the size of the largest Kuiper belt object". HST proposal 9678, Mikulski Archive for Space Telescopes. https://www.stsci.edu/hst/phase2-public/9678.prop [^unicode2022]: Anderson, D. (4 May 2022). "Out of this world: New astronomy symbols approved for the Unicode Standard". Unicode blog. http://blog.unicode.org/2022/05/out-of-this-world-new-astronomy-symbols.html [^delsanti2006]: Delsanti, A.; Jewitt, D. (2006). "The Solar System beyond the planets". In Blondel, P.; Mason, J. (eds.), *Solar System Update*. Springer, pp. 267–293. https://doi.org/10.1007/3-540-37683-6_11 [^levison2008]: Levison, H. F.; Morbidelli, A.; Van Laerhoven, C.; Gomes, R.; Tsiganis, K. (2008). "Origin of the structure of the Kuiper belt during a dynamical instability in the orbits of Uranus and Neptune". *Icarus* 196: 258–273. https://doi.org/10.1016/j.icarus.2007.11.035 [^brown2004]: Brown, M. E.; Trujillo, C. A. (2004). "Direct measurement of the size of the large Kuiper belt object (50000) Quaoar". *The Astronomical Journal* 127: 2413–2417. https://doi.org/10.1086/382513 [^stansberry2008]: Stansberry, J.; Grundy, W.; Brown, M.; et al. (2008). "Physical properties of Kuiper belt and Centaur objects: Constraints from the Spitzer Space Telescope". In *The Solar System Beyond Neptune*. University of Arizona Press, pp. 161–179. https://www.lpi.usra.edu/books/ssbn2008/7017.pdf [^fraser2010]: Fraser, W. C.; Brown, M. E. (2010). "Quaoar: A rock in the Kuiper belt". *The Astrophysical Journal* 714: 1547–1550. https://doi.org/10.1088/0004-637X/714/2/1547 [^fornasier2013]: Fornasier, S.; Lellouch, E.; Müller, T.; et al. (2013). "'TNOs are cool': A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70–500 μm". *Astronomy & Astrophysics* 555: A15. https://doi.org/10.1051/0004-6361/201321329 [^braga2013]: Braga-Ribas, F.; Sicardy, B.; Ortiz, J. L.; et al. (2013). "The size, shape, albedo, density, and atmospheric limit of transneptunian object (50000) Quaoar from multi-chord stellar occultations". *The Astrophysical Journal* 773: 26. https://doi.org/10.1088/0004-637X/773/1/26 [^kiss2024]: Kiss, C.; Müller, T. G.; Marton, G.; et al. (2024). "The visible and thermal light curve of the large Kuiper belt object (50000) Quaoar". *Astronomy & Astrophysics* 684: A50. https://doi.org/10.1051/0004-6361/202348054 [^margoti2026]: Margoti, G.; Braga-Ribas, F.; Ortiz, J. L.; Sicardy, B.; Desmars, J.; et al. (2026). "Size, shape, density, and atmospheric limit of (50000) Quaoar revealed from 14 years of stellar occultation". arXiv:2607.06450. https://arxiv.org/abs/2607.06450 [^castillo2007]: Castillo-Rogez, J. C.; Matson, D. L.; Sotin, C.; et al. (2007). "Iapetus' geophysics: Rotation rate, shape, and equatorial ridge". *Icarus* 190: 179–202. https://doi.org/10.1016/j.icarus.2007.02.018 [^ortiz2003]: Ortiz, J. L.; Gutiérrez, P. J.; Sota, A.; Casanova, V.; Teixeira, V. R. (2003). "Rotational brightness variations in trans-Neptunian object 50000 Quaoar". *Astronomy & Astrophysics* 409: L13–L16. https://doi.org/10.1051/0004-6361:20031253 [^proudfoot2025w]: Proudfoot, B.; Grundy, W.; Ragozzine, D.; Fernández-Valenzuela, E. (2025). "Beyond point masses. V. Weywot's non-Keplerian orbit". *The Planetary Science Journal*, accepted. arXiv:2511.07351. https://arxiv.org/abs/2511.07351 [^jewitt2004]: Jewitt, D. C.; Luu, J. (2004). "Crystalline water ice on the Kuiper belt object (50000) Quaoar". *Nature* 432: 731–733. https://doi.org/10.1038/nature03111 [^hussmann2006]: Hussmann, H.; Sohl, F.; Spohn, T. (2006). "Subsurface oceans and deep interiors of medium-sized outer planet satellites and large trans-neptunian objects". *Icarus* 185: 258–273. https://doi.org/10.1016/j.icarus.2006.06.005 [^schaller2007]: Schaller, E. L.; Brown, M. E. (2007). "Detection of methane on Kuiper belt object (50000) Quaoar". *The Astrophysical Journal* 670: L49–L51. https://doi.org/10.1086/524140 [^emery2024]: Emery, J. P.; Wong, I.; Brunetto, R.; et al. (2024). "A tale of 3 dwarf planets: Ices and organics on Sedna, Gonggong, and Quaoar from JWST spectroscopy". *Icarus* 414: 116017. https://doi.org/10.1016/j.icarus.2024.116017 [^fraser2013]: Fraser, W. C.; Trujillo, C.; Stephens, A. W.; et al. (2013). "Limits on Quaoar's atmosphere". *The Astrophysical Journal Letters* 774: L18. https://doi.org/10.1088/2041-8205/774/2/L18 [^arimatsu2019]: Arimatsu, K.; Ohsawa, R.; Hashimoto, G. L.; et al. (2019). "New constraint on the atmosphere of (50000) Quaoar from a stellar occultation". *The Astronomical Journal* 158: 236. https://doi.org/10.3847/1538-3881/ab5058 [^iauc8812]: Green, D. W. E. (22 February 2007). "IAUC 8812: Satellites of 2003 AZ84, (50000), (55637), and (90482)". *IAU Circular*. http://www.cbat.eps.harvard.edu/iauc/08800/08812.html [^street2008]: Street, N. (August 2008). "Heavenly bodies and the people of the Earth". *Search Magazine*. http://www.searchmagazine.org/Archives/Back%20Issues/2008%20July-August/full-heavenly-bodies.html [^proudfoot2025m]: Proudfoot, B.; Nolthenius, R.; Holler, B. J.; et al. (2025). "Orbital characterization of a newly discovered small satellite around Quaoar". *The Astrophysical Journal Letters* 993: L38. https://doi.org/10.3847/2041-8213/ae1585 [^fernandez2023]: Fernández-Valenzuela, E.; Holler, B.; Ortiz, J. L.; et al. (2023). "Weywot: the darkest known satellite in the trans-Neptunian region". *55th Meeting of the AAS Division for Planetary Sciences*. https://submissions.mirasmart.com/DPS55/Itinerary/PresentationDetail.aspx?evdid=75 [^braga2025]: Braga-Ribas, F.; Vachier, F.; Desmars, J.; Margoti, G.; Sicardy, B. (2025). "Investigating the formation of small Solar System objects using stellar occultations by satellites: present, future and its use to update satellite orbits". *Philosophical Transactions of the Royal Society A* 383: 20240200. https://doi.org/10.1098/rsta.2024.0200 [^nolthenius2025]: Nolthenius, R.; Bender, K.; Cotton, D. V.; Proudfoot, B. C. N.; Irwin, J. (2025). "Discovery of a new satellite or ring arc around (50000) Quaoar". *Research Notes of the AAS* 9: 226. https://doi.org/10.3847/2515-5172/adfeda [^braga2026]: Braga-Ribas, F.; Pereira, C. L.; Sicardy, B.; et al. (2026). "Evidence of a new arc or a belt of small satellites around (50000) Quaoar". *The Astrophysical Journal Letters* 999: L39. https://doi.org/10.3847/2041-8213/ae4751 [^madeira2026]: Madeira, G.; Esteves, L.; Morgado, B. E.; et al. (2026). "Dynamical implications of the recently detected feature around Quaoar and constraints on the presence of additional satellites". *The Planetary Science Journal* 7: 168. https://doi.org/10.3847/PSJ/ae81a8 [^morgado2023]: Morgado, B. E.; Sicardy, B.; Braga-Ribas, F.; et al. (2023). "A dense ring of the trans-Neptunian object Quaoar outside its Roche limit". *Nature* 614: 239–243. https://doi.org/10.1038/s41586-022-05629-6 [^pereira2023]: Pereira, C. L.; Sicardy, B.; Morgado, B. E.; et al. (2023). "The two rings of (50000) Quaoar". *Astronomy & Astrophysics* 673: L4. https://doi.org/10.1051/0004-6361/202346365 [^esa2023]: European Space Agency (8 February 2023). "ESA's Cheops finds an unexpected ring around dwarf planet Quaoar". https://www.esa.int/Science_Exploration/Space_Science/Cheops/ESA_s_Cheops_finds_an_unexpected_ring_around_dwarf_planet_Quaoar [^jhuapl2016]: Johns Hopkins Applied Physics Laboratory (31 August 2016). "New Horizons spies a Kuiper belt companion". http://pluto.jhuapl.edu/Multimedia/Science-Photos/image.php?gallery_id=2&image_id=459 [^mcgranaghan2011]: McGranaghan, R.; Sagan, B.; Dove, G.; et al. (2011). "A survey of mission opportunities to trans-Neptunian objects". *Journal of the British Interplanetary Society* 64: 296–303. Bibcode 2011JBIS...64..296M. [^brandt2017]: Brandt, P. C.; McNutt, R.; Hallinan, G.; et al. (2017). "The Interstellar Probe mission: Humanity's first explicit step in reaching another star". *Planetary Science Vision 2050 Workshop*, Lunar and Planetary Institute. https://www.hou.usra.edu/meetings/V2050/pdf/8173.pdf [^jones2021]: Jones, A. (16 April 2021). "China to launch a pair of spacecraft towards the edge of the solar system". *SpaceNews*. https://spacenews.com/china-to-launch-a-pair-of-spacecraft-towards-the-edge-of-the-solar-system/ ## External links - JPL Small-Body Database: 50000 Quaoar. https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=50000 - Trujillo, C. A. "Frequently asked questions about Quaoar". http://www.chadtrujillo.com/quaoar/ - ESA: Cheops finds an unexpected ring around dwarf planet Quaoar. https://www.esa.int/Science_Exploration/Space_Science/Cheops/ESA_s_Cheops_finds_an_unexpected_ring_around_dwarf_planet_Quaoar - Minor Planet Center: 50000 Quaoar. https://www.minorplanetcenter.net/db_search/show_object?object_id=50000 ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Quaoar) : [Wikitube](https://en.wikitube.io/wiki/Quaoar) · pinned revision [1375152540](https://en.wikipedia.org/w/index.php?oldid=1375152540) · 2026-09-18 ## Previous hub tags Hubs: `Life_Physics`. Portals: [[PORTAL_Solar_System]]. --- *Solar System portal child articles, wave 1 · 2026-09-18 · drafted · row SOL-073 · explorer state `?obj=Quaoar`.*