Haumea, officially designated as minor planet 136108 Haumea, is a dwarf planet situated beyond Neptune's orbital path. Its initial discovery occurred in 2004 by a Caltech team led by Mike Brown at the Palomar Observatory. Subsequently, in 2005, a team directed by José Luis Ortiz Moreno at Spain's Sierra Nevada Observatory formally announced its identification, having located it in precovery images from 2003. Following this announcement, it was assigned the provisional designation 2003 EL61.
Haumea (minor-planet designation: 136108 Haumea) is a dwarf planet located beyond Neptune's orbit. It was discovered in 2004 by a team headed by Mike Brown of Caltech at the Palomar Observatory, and formally announced in 2005 by a team headed by José Luis Ortiz Moreno at the Sierra Nevada Observatory in Spain, who had discovered it that year in precovery images taken by the team in 2003. From that announcement, it received the provisional designation 2003 EL61.
On September 17, 2008, the International Astronomical Union (IAU) officially named the object Haumea, after the Hawaiian goddess of childbirth and fertility, anticipating its classification as a dwarf planet. Current estimations position Haumea as the third-largest known trans-Neptunian object, following Eris and Pluto, with a size comparable to Titania, one of Uranus's moons. Historical precovery images of Haumea have been traced as far back as March 22, 1955.
Haumea possesses a mass approximately one-third that of Pluto and 1/1400th that of Earth. While its precise shape remains unobserved directly, analyses of its light curve suggest a form consistent with a Jacobi ellipsoid—a shape characteristic of a dwarf planet—where its major axis is twice the length of its minor axis. In October 2017, astronomers reported the detection of a ring system encircling Haumea, marking the inaugural discovery of such a system around both a trans-Neptunian object and a dwarf planet.
Until recently, Haumea's gravitational force was presumed adequate for it to achieve hydrostatic equilibrium; however, this assessment is now uncertain. The dwarf planet's elongated morphology, rapid rotational period, discernible rings, and elevated albedo (attributable to a surface composed of crystalline water ice) are hypothesized to be the outcomes of a colossal impact event. This collision is believed to have established Haumea as the most substantial constituent of a collisional family, known as the Haumea family, which encompasses several prominent trans-Neptunian objects and its two identified moons, Hiʻiaka and Namaka.
Historical Context
Discovery
The discovery of Haumea is attributed to two distinct research teams. One team, comprising Mike Brown from Caltech, David Rabinowitz from Yale University, and Chad Trujillo from the Gemini Observatory in Hawaii, identified Haumea on December 28, 2004, within images captured on May 6, 2004. Subsequently, on July 20, 2005, this team disseminated an online abstract detailing their findings, which they intended to formally present at a conference in September 2005.
Concurrently, José Luis Ortiz Moreno and his research group at the Instituto de Astrofísica de Andalucía, situated at the Sierra Nevada Observatory in Spain, located Haumea in images acquired between March 7 and 10, 2003. Ortiz subsequently communicated their discovery to the Minor Planet Center via email on the evening of July 27, 2005.
Initially, Brown acknowledged Ortiz's claim to discovery. However, Brown later developed suspicions of fraudulent conduct by the Spanish team after discovering that the Sierra Nevada Observatory had accessed his observation logs the day prior to their discovery announcement. This access, a detail not disclosed in their announcement, was contrary to standard practice. The logs contained sufficient data for the Ortiz team to identify Haumea in their 2003 images. Furthermore, these logs were accessed again shortly before Ortiz arranged telescope time to acquire confirmatory images for a subsequent announcement to the MPC on July 29. Ortiz subsequently confirmed accessing the Caltech observation logs but refuted any impropriety, asserting that his intention was solely to verify the identification of a novel celestial body.
According to International Astronomical Union (IAU) protocol, discovery credit for a minor planet is granted to the first entity that submits a report to the Minor Planet Center (MPC) containing adequate positional data for accurate orbital determination. The credited discoverer typically holds priority in selecting a name. Nevertheless, the IAU's announcement on September 17, 2008, regarding Haumea's naming by a joint committee established for prospective dwarf planets, notably omitted any mention of a specific discoverer. While the Sierra Nevada Observatory, associated with the Spanish team, was cited as the discovery location, the adopted name, Haumea, originated from the Caltech proposal. Ortiz's team had suggested "Ataecina," an ancient Iberian goddess of spring; this chthonic deity would have been suitable for a plutino, a classification that Haumea does not fit.
Nomenclature and Designation
Prior to its official naming, the Caltech discovery team internally referred to it as "Santa" due to its discovery on December 28, 2004, shortly after Christmas. Conversely, the Spanish team submitted the initial discovery claim to the Minor Planet Center in July 2005. Consequently, on July 29, 2005, Haumea received the provisional designation 2003 EL61, derived from the date of the Spanish team's discovery image. Subsequently, on September 7, 2006, it was formally cataloged and numbered as (136108) 2003 EL61 within the official minor planet registry.
Adhering to the then-current International Astronomical Union (IAU) guidelines, which mandated that classical Kuiper belt objects be named after mythological creation deities, in September 2006, the Caltech team proposed names derived from Hawaiian mythology to the IAU for both (136108) 2003 EL61 and its satellites, intending "to pay homage to the place where the satellites were discovered". These names were put forward by David Rabinowitz, a member of the Caltech team. Haumea, the matron goddess of Hawaiʻi Island, is associated with Mauna Kea, the site of the Gemini and W. M. Keck Observatories. Furthermore, her identification with Papa, the earth goddess and consort of Wākea (space), was deemed fitting at the time, given the prevailing hypothesis that Haumea consisted almost entirely of solid rock, lacking the substantial ice mantle over a small rocky core characteristic of other known Kuiper belt objects. Finally, Haumea's role as the goddess of fertility and childbirth, whose numerous offspring emerged from various parts of her body, aligns metaphorically with the hypothesized swarm of icy fragments believed to have detached from the main body during an ancient collision. Consequently, the two identified moons, also presumed to have formed through this process, bear the names of two of Haumea's daughters: Hiʻiaka and Nāmaka.
The Ortiz team's proposed name, Ataecina, failed to satisfy IAU naming conventions because chthonic deity names were exclusively allocated to stably resonant trans-Neptunian objects, such as plutinos, which exhibit a 3:2 resonance with Neptune. Haumea, however, displayed an intermittent 7:12 resonance, rendering it non-resonant by certain definitions. These naming criteria were subsequently clarified in late 2019, when the IAU stipulated that chthonic figures should be reserved specifically for plutinos.
Haumea's planetary symbol, ⟨⟩, is codified in Unicode as U+1F77B. While planetary symbols are largely obsolete in contemporary astronomy, 🝻 primarily finds use among astrologers, though it has also appeared in NASA contexts. This symbol was conceived by Denis Moskowitz, a Massachusetts-based software engineer, through the combination and simplification of Hawaiian petroglyphs representing 'woman' and 'childbirth'.
Orbit
Haumea exhibits an orbital period of 284 Earth years, a perihelion of 35 AU, and an orbital inclination of 28°. The object reached its aphelion in early 1992 and is presently situated over 50 AU from the Sun. Its next perihelion passage is projected for 2133. Haumea's orbit displays a marginally higher eccentricity compared to other constituents of its collisional family. This phenomenon is attributed to Haumea's subtle 7:12 orbital resonance with Neptune, which has progressively altered its primordial orbit over approximately a billion years via the Kozai effect, facilitating the exchange between orbital inclination and increased eccentricity.
Possessing a visual magnitude of 17.3, Haumea ranks as the third-brightest object in the Kuiper belt, following Pluto and Makemake, and is readily discernible with a substantial amateur telescope. Nevertheless, owing to the shared orbital alignment of planets and most small Solar System bodies, originating from their formation within the primordial Solar System disk, initial surveys for distant objects predominantly concentrated on the celestial projection of this common plane, known as the ecliptic. Upon thorough exploration of the sky region near the ecliptic, subsequent astronomical surveys commenced targeting objects dynamically perturbed into higher-inclination orbits, alongside more distant bodies exhibiting slower apparent motions across the celestial sphere. Ultimately, these comprehensive surveys encompassed Haumea's location, characterized by its significant orbital inclination and its present distant position relative to the ecliptic.
Haumea's long-term orbital stability throughout the Solar System's lifespan is improbable. A simulation investigating the future trajectories of 34 trans-Neptunian objects indicated that Haumea possessed the highest statistical probability of being ejected from its orbit into either interstellar space or the inner Solar System within the next billion years.
Possible resonance with Neptune
Haumea is hypothesized to maintain an intermittent 7:12 orbital resonance with Neptune. The ascending node, denoted as Ω, undergoes precession over approximately 4.6 million years. This resonance is disrupted twice within each precession cycle, occurring roughly every 2.3 million years, before re-establishing itself after approximately one hundred thousand years. Consequently, due to its inherent instability, Marc Buie classifies this interaction as non-resonant.
Rotation
Haumea exhibits significant luminosity variations over a 3.9-hour interval, which are exclusively attributable to a rotational period of this duration. This rotational velocity surpasses that of any other known equilibrium body within the Solar System, and indeed, any other celestial object exceeding 100 km in diameter. Whereas most rotating bodies in hydrostatic equilibrium assume an oblate spheroid shape, Haumea's exceptionally rapid rotation causes it to deform into a triaxial ellipsoid. Should Haumea's rotation accelerate further, it would likely deform into a dumbbell configuration and subsequently fragment. The genesis of this rapid rotation is hypothesized to be the impact event responsible for the formation of its satellites and associated collisional family.
Currently, Haumea's equatorial plane is observed nearly edge-on from Earth and exhibits a slight offset relative to the orbital planes of its ring and its outermost moon, Hiʻiaka. While Ragozzine and Brown (2009) initially posited coplanarity with Hiʻiaka's orbital plane, their models for the collisional genesis of Haumea's satellites consistently indicated an alignment of Haumea's equatorial plane with Hiʻiaka's orbital plane to within approximately 1°. This hypothesis was corroborated by observations from a 2017 stellar occultation by Haumea, which unveiled a ring system roughly coincident with the orbital plane of Hiʻiaka and Haumea's equator. Subsequent mathematical analysis of the occultation data by Kondratyev and Kornoukhov (2018) established constraints on the relative inclination angles of Haumea's equator with respect to the orbital planes of its ring and Hiʻiaka, determining them to be 3.2°±1.4° and 2.0°±1.0°, respectively, relative to Haumea's equator.
Physical characteristics
Size, shape, and composition
The dimensions of a Solar System object can be inferred from its optical magnitude, heliocentric distance, and albedo. Celestial bodies appear luminous to terrestrial observers either due to their substantial size or their high reflectivity. Should their reflectivity (albedo) be determined, a preliminary estimation of their size becomes feasible. While the albedo remains undetermined for most distant objects, Haumea's considerable size and brightness permit the measurement of its thermal emission, thereby yielding an approximate value for its albedo and, consequently, its size. Nevertheless, the precise calculation of its dimensions is intricate due to its rapid rotational velocity. The principles of rotational physics for deformable bodies predict that a celestial object rotating at Haumea's speed will achieve the equilibrium form of a triaxial ellipsoid within a period as brief as one hundred days. It is hypothesized that the majority of Haumea's brightness fluctuations result not from localized albedo variations but from the alternating presentation of its side and end views as observed from Earth.
The rotational characteristics and the amplitude of Haumea's light curve have been posited to impose significant constraints on its internal composition. Assuming Haumea were in hydrostatic equilibrium and possessed a low density akin to Pluto's—featuring a substantial ice mantle overlying a small rocky core—its swift rotation would have induced a greater degree of elongation than is consistent with its observed brightness fluctuations. These considerations thus limited its density to a range of 2.6–3.3 g/cm3. In contrast, the Moon, a rocky body, exhibits a density of 3.3 g/cm3, while Pluto, representative of icy Kuiper belt objects, has a density of 1.86 g/cm§45§. Haumea's inferred high density encompasses values characteristic of silicate minerals like olivine and pyroxene, which constitute numerous rocky bodies within the Solar System. This further implied that Haumea's primary composition is rock, overlaid by a comparatively thin ice layer. It is plausible that a thick ice mantle, more characteristic of other Kuiper belt objects, was ejected during the impact event that subsequently formed the Haumean collisional family.
The presence of Haumea's moons enables the determination of the system's total mass through the application of Kepler's third law to their orbital parameters. This calculation yields a mass of 4.2×1021 kg, which constitutes 28% of the Plutonian system's mass and 6% of the Moon's mass. The vast majority of this mass is attributed to Haumea itself. Multiple ellipsoid-model calculations have been conducted to ascertain Haumea's dimensions. The initial model, developed post-discovery from ground-based optical light curve observations, indicated a total length ranging from 1,960 to 2,500 km and a visual albedo (pv) exceeding 0.6. A triaxial ellipsoid shape, with approximate dimensions of 2,000 × 1,500 × 1,000 km and an albedo of 0.71, was subsequently identified as the most probable configuration. Observations performed by the Spitzer Space Telescope, utilizing photometry at infrared wavelengths of 70 μm, determined a diameter of 1,150+250
−100 km and an albedo of 0.84+0.1
−0.2. Subsequent analyses of light curves proposed an equivalent circular diameter of 1,450 km. In 2010, a comprehensive analysis integrating measurements from the Herschel Space Telescope with earlier Spitzer Telescope data provided a revised estimate for Haumea's equivalent diameter, approximately 1,300 km. These independent size estimations converge around an average geometric mean diameter of approximately 1,400 km. By 2013, the Herschel Space Telescope refined its measurement of Haumea's equivalent circular diameter to approximately 1,240+69
−58 km.
Nevertheless, observations from a stellar occultation in January 2017 introduced considerable uncertainty regarding these prior conclusions. While Haumea's measured shape retained its previously assumed elongated form, its dimensions appeared substantially larger. Data derived from the occultation indicated that Haumea's longest axis approximates Pluto's diameter, while its polar diameter is roughly half that. The density subsequently calculated from Haumea's observed shape was approximately 1.8 g/cm3, which aligns more closely with the densities of other substantial Trans-Neptunian Objects (TNOs). This derived shape, however, seemed incompatible with a homogeneous body in hydrostatic equilibrium. Despite this, Haumea remains recognized as one of the largest trans-Neptunian objects discovered, being smaller than Eris and Pluto, comparable in size to Makemake and potentially Gonggong, and larger than Sedna, Quaoar, and Orcus.
In 2019, a research endeavor sought to reconcile the disparate measurements of Haumea's shape and density through numerical modeling, treating Haumea as a differentiated celestial body. This study determined that dimensions of approximately 2,100 × 1,680 × 1,074 km (with the long axis modeled at 25 km intervals) provided the optimal fit for Haumea's observed shape during the 2017 occultation. Crucially, these dimensions also proved consistent with both the surface and core exhibiting scalene ellipsoid shapes in hydrostatic equilibrium. The refined model of Haumea's morphology suggests the presence of a core measuring approximately 1,626 × 1,446 × 940 km, characterized by a comparatively high density of approximately 2.68 g/cm3. This density implies a composition predominantly of hydrated silicates, such as kaolinite. Encircling this core is an icy mantle, varying in thickness from about 70 km at the poles to 170 km along Haumea's longest axis, and constituting up to 17% of its total mass. Haumea's estimated mean density is approximately 2.018 g/cm§910§, accompanied by an albedo of approximately 0.66.
Surface Characteristics
In 2005, spectral data acquired by the Gemini and Keck telescopes revealed prominent features of crystalline water ice on Haumea's surface, closely resembling those observed on Charon, Pluto's moon. This finding is anomalous, given that crystalline ice typically forms at temperatures exceeding 110 K, whereas Haumea's surface temperature remains below 50 K, a regime conducive to the formation of amorphous ice. Furthermore, the structural integrity of crystalline ice is compromised by the continuous influx of cosmic rays and energetic solar particles impacting trans-Neptunian objects. The estimated timescale for crystalline ice to transition back to an amorphous state under such bombardment is approximately ten million years, a stark contrast to the billions of years that trans-Neptunian objects have occupied their current frigid orbital positions.
Radiation-induced damage is anticipated to cause reddening and darkening of the surfaces of trans-Neptunian objects, particularly when common surface constituents like organic ices and tholin-like compounds are present, as exemplified by Pluto. Consequently, Haumea's observed spectra and color imply that it, along with its associated family members, has experienced recent resurfacing events, resulting in the exposure of fresh ice. Nevertheless, a credible mechanism to explain this resurfacing phenomenon has yet to be proposed.
Haumea exhibits a high albedo, ranging from 0.6 to 0.8, which is indicative of crystalline ice. Other large Trans-Neptunian Objects (TNOs), such as Eris, possess comparable or greater albedos. Spectral modeling suggests that 66% to 80% of Haumea's surface is composed of pure crystalline water ice, with potential contributors to this high albedo including hydrogen cyanide or phyllosilicate clays. The presence of inorganic cyanide salts, such as copper potassium cyanide, is also hypothesized.
Subsequent investigations utilizing visible and near-infrared spectroscopy, however, propose a homogeneous surface composed of an intimate 1:1 mixture of amorphous and crystalline ice, alongside a maximum of 8% organic compounds. The non-detection of ammonia hydrate precludes cryovolcanic activity. These observations corroborate dynamic studies, indicating the collisional event occurred over 100 million years ago. Furthermore, the lack of detectable methane in Haumea's spectra aligns with a warm collisional history, which would have dissipated such volatile compounds, unlike the conditions observed on Makemake.
While Haumea's light curve exhibits significant fluctuations attributable to its irregular shape, uniformly impacting all wavelengths, distinct, localized color variations observed across visible and near-infrared spectra reveal a surface region with divergent chromatic and albedo characteristics. Specifically, a prominent dark red area was identified on Haumea's otherwise bright white surface in September 2009. This feature, potentially an impact site, suggests a concentration of minerals and organic (carbon-rich) compounds, or alternatively, a higher abundance of crystalline ice. Consequently, Haumea's surface may exhibit a mottled appearance, analogous to Pluto's, albeit less pronounced.
Ring
The existence of a circumplanetary ring around Haumea was inferred from a stellar occultation observed on January 21, 2017, and subsequently detailed in an October 2017 Nature publication. This discovery marks the first identification of a ring system orbiting a Trans-Neptunian Object (TNO). Characterized by a radius of approximately 2,287 km, a width of about 70 km, and an opacity of 0.5, the ring resides well within Haumea's Roche limit. This limit, estimated at roughly 4,400 km for a spherical body, is extended further due to Haumea's non-spherical shape.
The ring's orbital plane exhibits an inclination of 3.2°±1.4° relative to Haumea's equatorial plane, closely aligning with the orbital plane of its larger, outer satellite, Hiʻiaka. Furthermore, the ring is situated near the 1:3 orbit-spin resonance with Haumea's rotation, corresponding to a radial distance of 2,285 ± 8 km from Haumea's center. Its contribution to Haumea's overall brightness is estimated at 2.5%.
A 2019 study by Othon Cabo Winter and collaborators, investigating the dynamics of ring particles, demonstrated that while the 1:3 resonance with Haumea's rotation is dynamically unstable, a stable region exists within the phase space that corresponds to the observed location of Haumea's ring. This finding suggests that the ring particles occupy circular, periodic orbits positioned in proximity to, but not within, the resonance.
Satellites
Haumea is orbited by two small satellites: (136108) Haumea I, designated Hiʻiaka, and (136108) Haumea II, named Namaka. Both satellites were identified in 2005 by Darin Ragozzine and Michael Brown, utilizing observations of Haumea conducted at the W. M. Keck Observatory.
Hiʻiaka, initially nicknamed "Rudolph" by the Caltech research team, was discovered on January 26, 2005. As the outer, larger, and brighter of the two satellites, with an approximate diameter of 310 km, Hiʻiaka completes a nearly circular orbit around Haumea every 49 days. Prominent absorption features observed at 1.5 and 2 micrometers in its infrared spectrum are indicative of a surface largely covered by nearly pure crystalline water ice. This distinctive spectrum, coupled with analogous absorption lines detected on Haumea, prompted Brown and his collaborators to infer that a capture scenario was improbable for the system's formation, suggesting instead that the Haumean moons originated as fragments of Haumea itself.
Namaka, Haumea's smaller, inner satellite, was identified on June 30, 2005, and informally named "Blitzen". With approximately one-tenth the mass of Hiʻiaka, Namaka completes an 18-day orbit around Haumea in a highly elliptical, non-Keplerian trajectory. As of 2008, its orbit was inclined 13° relative to the larger moon, which exerts a perturbing influence. The observed substantial eccentricities and mutual inclination of the satellites' orbits are anomalous, as tidal effects would typically lead to their damping. A recent encounter with a 3:1 resonance with Hiʻiaka could potentially account for the currently excited orbital states of the Haumean moons.
Between approximately 2008 and 2011, the orbits of the Haumean moons were observed nearly edge-on from Earth, resulting in periodic occultations of Haumea by Namaka. Such transit observations would have yielded precise data on the size and morphology of Haumea and its satellites, mirroring similar events involving Pluto and Charon in the late 1980s. Detecting the minute alteration in the system's luminosity during these occultations would have necessitated a professional telescope of at least medium aperture. Hiʻiaka's most recent occultation of Haumea occurred in 1999, preceding its discovery by several years, and is not anticipated to recur for approximately 130 years. Uniquely among regular satellites, Namaka's orbit experienced significant torque from Hiʻiaka, thereby maintaining the favorable viewing geometry for Namaka–Haumea transits for an extended period. A single occultation event was documented on June 19, 2009, by the Pico dos Dias Observatory in Brazil.
Collisional family
Haumea represents the largest constituent of its collisional family, an assemblage of celestial bodies sharing comparable physical and orbital attributes, hypothesized to have originated from the fragmentation of a larger progenitor object due to an impact event. This family, the inaugural one identified among Trans-Neptunian Objects (TNOs), comprises—in addition to Haumea and its satellites—(55636) 2002 TX300 (≈364 km), (24835) 1995 SM55 (≈174 km), (19308) 1996 TO66 (≈200 km), (120178) 2003 OP32 (≈230 km), and (145453) 2005 RR43 (≈252 km). Brown and collaborators posited that the family directly resulted from the impact responsible for stripping Haumea's ice mantle. However, an alternative hypothesis proposes a more intricate genesis: that the material expelled during the initial collision subsequently coalesced into a substantial moon of Haumea, which was then fragmented in a secondary collision, scattering its debris. This latter scenario seemingly generates a velocity dispersion among the fragments that more accurately corresponds to the observed velocity dispersion of the family's constituents.
The existence of this collisional family suggests a potential origin for Haumea and its associated bodies within the scattered disc. Within the contemporary, sparsely distributed Kuiper belt, the probability of such an impact occurring throughout the Solar System's history is below 0.1 percent. Formation of the family within the denser primordial Kuiper belt is improbable, as such a tightly bound group would have been disrupted by Neptune's migration into the belt, which is considered the reason for the belt's present low density. Consequently, it seems plausible that the dynamic scattered disc region, where the likelihood of such a collision is considerably elevated, served as the birthplace for the progenitor object that yielded Haumea and its related members.
Given that the group's observed diffusion would have required a minimum of one billion years, the impact event responsible for the formation of the Haumea family is estimated to have transpired at least that far in the past.
Exploration
The New Horizons spacecraft conducted distant observations of Haumea in October 2007, January 2017, and May 2020, at respective distances of 49 AU, 59 AU, and 63 AU. The spacecraft's trajectory, moving away from the inner Solar System, facilitated observations of Haumea at high phase angles, which are otherwise inaccessible from Earth. This allowed for the characterization of Haumea's surface light scattering properties and phase curve behavior.
A flyby mission to Haumea could achieve its destination in 16.45 years if launched on November 1, 2026; September 23, 2037; or October 29, 2038. Haumea is considered a potential target for future exploration missions, exemplified by preliminary studies investigating a probe concept for Haumea and its moons (situated at 35–51 AU). Critical technological considerations for such missions include probe mass, power generation, and propulsion systems.
20000 Varuna: A substantial, rapidly rotating trans-Neptunian object characterized by an elongated ellipsoidal morphology.
- 20000 Varuna – a large, rapidly-rotating trans-Neptunian object with an elongated ellipsoid shape
- 208996 Achlys: Another considerable, swiftly rotating trans-Neptunian object exhibiting an elongated ellipsoidal form analogous to Haumea.
- Astronomical naming conventions
- How I Killed Pluto and Why It Had It Coming: A memoir authored by Mike Brown, published in 2010.
- List of Solar System objects by size
Notes
References
Information regarding (136108) Haumea, Hiʻiaka, and Namaka (last updated September 21, 2014).
- (136108) Haumea, Hiʻiaka, and Namaka at Johnston's Archive.com (updated 21 September 2014)
- Podcast from the International Year of Astronomy 2009: Dwarf Planet Haumea, featuring Darin Ragozzine.
- An observation of Haumea conducted on June 10, 2011, by Mike Brown using the 4.20-meter (165-inch) WHT, documented a brightness dip between approximately 0:30 and 3:30. This phenomenon is attributed to Namaka transiting Haumea. While Hiʻiaka, the outer moon, was blended in the images, its 4.5-hour rotational period introduced minor luminosity variations.
- This animation depicts the intermittent 7:12 orbital resonance between Haumea and Neptune, projecting its dynamics over the subsequent 3.5 million years.