541132 Leleākūhonua

• 1. Discovery And Observation

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  Astronomers David Tholen, Chad Trujillo and Scott Sheppard spotted a faint point of light on the 13th of October 2015. They were using the Subaru Telescope at Mauna Kea Observatories in Hawaii. The object appeared during an astronomical survey designed to find things beyond the Kuiper Cliff. It was so distant that it took years to confirm its path around the Sun. The team did not announce their finding until the 1st of October 2018. By then they had used follow-up telescopes like Magellan and Lowell Discovery to map its trajectory. The provisional designation 2015 BP519 led them to call it "The Goblin" informally before any official name existed.

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• 2. Orbital Mechanics And Classification

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  Leleākūhonua travels from 65 AU out to about 2800 AU over a period of roughly 55,000 years. Its orbit stretches with an eccentricity of 0.955 and tilts at an inclination relative to the ecliptic plane. This extreme shape places it among the sednoids found in the outer Solar System. It is only the third such object discovered after Sedna and another unnamed body. The distance varies wildly as it swings close to the Sun and then drifts far away. Current data shows it sits inbound at 78 AU from the Sun today. That position is more than two-and-a-half times farther out than Pluto currently resides.

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• 3. Implications For Planet Nine

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  The orbital path suggests but does not prove the existence of a hypothetical ninth planet. Other distant trans-Neptunian objects share similar orbits that point toward this possibility. Sheppard and his colleagues concluded the discovery implies a population of about 2 million inner Oort cloud objects larger than 100 kilometers. These objects would have a combined total mass equal to that of Pluto. This mass represents a fraction of Earth's moon weight yet several times the mass of the asteroid belt. Most of these potential objects remain too distant for contemporary technology to detect. Their presence might explain why Leleākūhonua follows such a stretched path around the Sun.

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• 4. Naming And Cultural Context

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  Students in the Hawaiian-language program A Hua He Inoa suggested the name Leleākūhonua on the 3rd of June 2020. The phrase translates to "it flies until land appears" using words like lele for fly, ā for until, kū for appear, and honua for land. They chose it because the object reminded them of the migrations of the kolea or Pacific golden plover. These birds travel from Alaska to Hawaii every year. The English description states the name compares the orbit to the flight of migratory birds seeking home. Although the Minor Planet Center listed it as a life form in the Kumulipo chant, the exact phrase does not actually occur there. It is a descriptive phrase created by students rather than an ancient text quote.

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• 5. Physical Dimensions And Albedo

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  The size of Leleākūhonua depends entirely on its assumed albedo or reflectivity value. If it is a darker object then it must be larger to reflect the same amount of light. Observations at Penticton Canada on the 20th of October 2018 showed a single-chord stellar occultation event. This data suggested a smaller diameter corresponding to a higher albedo of 0.21. Initial estimates placed it around 440 kilometers under an assumption of 0.15 albedo. The faint object has a visual magnitude of 24.64 comparable to Pluto's smaller moons. Higher reflectivity demands that the physical body be smaller while lower reflectivity requires it to be larger.

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