(516977) 2012 HZ84

Last updated
(516977) 2012 HZ84
2012 HZ84 by New Horizons.jpg
False-color image of 2012 HZ84 taken by
New Horizons in December 2017
Discovery [1]
Discovered by New Horizons KBO Search
Discovery site Las Campanas Obs.
Discovery date17 April 2012
Designations
(516977) 2012 HZ84
2012 HZ84
TNO [2]  ·NearScat [3]
cubewano [4]  · distant [1]
Orbital characteristics [2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 4 ·2 [1]
Observation arc 5.18 yr (1,893 d)
Aphelion 55.445 AU
Perihelion 37.219 AU
46.332 AU
Eccentricity 0.1967
315.38 yr (115,191 d)
321.81°
0° 0m 11.16s / day
Inclination 5.4328°
257.02°
86.064°
Physical characteristics
Mean diameter
74  km (est. at 0.09) [4]
8.9 [1] [2]

    (516977) 2012 HZ84 (provisional designation 2012 HZ84) is a small trans-Neptunian object from the Kuiper belt located in the outermost region of the Solar System, approximately 74 kilometers (46 miles) in diameter. It was discovered on 17 April 2012, by a team of astronomers using one of the Magellan Telescopes in Chile during the New Horizons KBO Search in order to find a potential flyby target for the New Horizons spacecraft. [1] In December 2017, this classical Kuiper belt object was imaged by the spacecraft from afar at a record distance from Earth. [5]

    Contents

    Orbit and classification

    2012 HZ84 orbits the Sun at a distance of 37.2–55.4  AU once every 315 years and 5 months (semi-major axis of 46.33 AU). Its orbit has an eccentricity of 0.20 and an inclination of 5.4° with respect to the ecliptic. [2]

    As a cubewano, also known as classical Kuiper belt object, [4] 2012 HZ84 is located in between the resonant plutino and twotino populations and has a low-eccentricity orbit. It belongs to the "stirred" hot population, but only just, since the rather arbitrary threshold to the cold population is typically defined for inclinations lower than 5°.

    In the object classification of the Deep Ecliptic Survey, however, 2012 HZ84 has a secured SCATNEAR type, which is a combination of the SCAT and NEAR attributes. It means that the object does not cross the orbit of Neptune but has a higher inclination and eccentricity (SCAT) than the survey's CLASSICAL type objects, and it currently interacts with the dominant ice giant Neptune (NEAR), contrary to the much less gravitationally affected objects of the EXTD type. [3]

    The body's observation arc begins with its first observation on 17 April 2012, made by astronomers David Osip, Paul Schechter, David Borncamp, Susan Benecchi and Scott Sheppard of the New Horizons KBO Search ( 268 ) team using the Magellan II (Clay) telescope at the Las Campanas Observatory, located in the Atacama desert in Chile. [1] [6]

    Milestone image

    Trajectory of New Horizons and other nearby Kuiper belt objects New Horizons KEM Trajectory.png
    Trajectory of New Horizons and other nearby Kuiper belt objects

    When the New Horizons spacecraft imaged 2012 HZ84 in 2017, it was the farthest from Earth ever captured by a spacecraft. The image was taken by the spacecraft's Long Range Reconnaissance Imager (LORRI) on 5 December 2017 at more than 6.12 billion kilometers (40.9 AU) away from Earth. This record was previously held by the Voyager 1 spacecraft which took the iconic Pale Blue Dot image at 6.06 billion kilometers from Earth in February 1990. [5]

    In December 2017, New Horizons also imaged the trans-Neptunian object 2012 HE85 , which was first observed by the same team of astronomers the night after they discovered 2012 HZ84. [5] Both objects held this record for little more than one year, until it was superseded on New Year's Eve 2018/19, when New Horizons made its close flyby of 486958 Arrokoth at a new record distance of 6.4 billion kilometers from Earth. [7]

    Numbering and naming

    This minor planet was numbered by the Minor Planet Center on 30 April 2018 and received the number 516977 in the minor planet catalog ( M.P.C. 110093). [8] As of 2020, it has not been named. [1]

    Physical characteristics

    According to Johnston's Archive, the object measures 74 kilometers in diameter based on an assumed albedo of 0.09 and an absolute magnitude of 8.9. [2] [4] As of 2019, no rotational lightcurve of 2012 HZ84 has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown. [2]

    Related Research Articles

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    A classical Kuiper belt object, also called a cubewano ( "QB1-o"), is a low-eccentricity Kuiper belt object (KBO) that orbits beyond Neptune and is not controlled by an orbital resonance with Neptune. Cubewanos have orbits with semi-major axes in the 40–50 AU range and, unlike Pluto, do not cross Neptune's orbit. That is, they have low-eccentricity and sometimes low-inclination orbits like the classical planets.

    <span class="mw-page-title-main">Kuiper belt</span> Area of the Solar System beyond the planets, comprising small bodies

    The Kuiper belt is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles, such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region.

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    A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has an orbital semi-major axis of 30.1 astronomical units (au).

    <span class="mw-page-title-main">28978 Ixion</span> Plutino

    28978 Ixion (, provisional designation 2001 KX76) is a large trans-Neptunian object and a possible dwarf planet. It is located in the Kuiper belt, a region of icy objects orbiting beyond Neptune in the outer Solar System. Ixion is classified as a plutino, a dynamical class of objects in a 2:3 orbital resonance with Neptune. It was discovered in May 2001 by astronomers of the Deep Ecliptic Survey at the Cerro Tololo Inter-American Observatory, and was announced in July 2001. The object is named after the Greek mythological figure Ixion, who was a king of the Lapiths.

    <span class="nowrap">(55565) 2002 AW<sub>197</sub></span> Classical Kuiper belt object

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    <span class="nowrap">(612911) 2004 XR<sub>190</sub></span> Minor planet in the scattered disc

    (612911) 2004 XR190, nicknamed Buffy, is a trans-Neptunian object, classified as both a scattered disc object and a detached object, located in the outermost region of the Solar System. It was first observed on 11 December 2004, by astronomers with the Canada–France Ecliptic Plane Survey at the Mauna Kea Observatories, Hawaii, United States. It is the largest known highly inclined (> 45°) object. With a perihelion of 51 AU, it belongs to a small and poorly understood group of very distant objects with moderate eccentricities.

    <span class="mw-page-title-main">15810 Arawn</span> Kuiper belt object observed by New Horizons

    15810 Arawn, provisional designation 1994 JR1, is a trans-Neptunian object (TNO) from the inner regions of the Kuiper belt, approximately 133 kilometres (83 mi) in diameter. It belongs to the plutinos, the largest class of resonant TNOs. It was named after Arawn, the ruler of the underworld in Welsh mythology, and discovered on 12 May 1994, by astronomers Michael Irwin and Anna Żytkow with the 2.5-metre Isaac Newton Telescope at Roque de los Muchachos Observatory in the Canary Islands, Spain.

    (35671) 1998 SN165 (provisional designation 1998 SN165) is a trans-Neptunian object from the Kuiper belt located in the outermost region of the Solar System. It was discovered on 23 September 1998, by American astronomer Arianna Gleason at the Kitt Peak National Observatory near Tucson, Arizona. The cold classical Kuiper belt object is a dwarf planet candidate, as it measures approximately 400 kilometers (250 miles) in diameter. It has a grey-blue color (BB) and a rotation period of 8.8 hours. As of 2021, it has not been named.

    <span class="mw-page-title-main">471143 Dziewanna</span> Scattered disc object

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    2011 HM102 is the ninth Neptune trojan discovered. It was first observed on 29 April 2011, during the New Horizons KBO Search (268) using the Magellan II (Clay) Telescope at Las Campanas Observatory in Chile. It has the same orbital period as Neptune and orbits at the L5 Lagrangian point about 60° backwards of Neptune.

    2011 KW48, temporarily designated VNH0004, is a trans-Neptunian object from the inner classical part of the Kuiper belt, located in the outermost region of the Solar System. It measures approximately 77 kilometers (48 mi) in diameter.

    420356 Praamzius, provisional designation 2012 BX85, is a trans-Neptunian object from the classical Kuiper belt, located in the outermost region of the Solar System, approximately 190–320 kilometers (120–200 miles) in diameter. It was discovered on 23 January 2012, by astronomers Kazimieras Černis and Richard Boyle with the Vatican's VATT at Mount Graham Observatory in Arizona, United States. The cold classical Kuiper belt object is a weak dwarf planet candidate and possibly very red in color. It was named after the chief god Praamžius from Lithuanian mythology.

    <span class="nowrap">2014 PN<sub>70</sub></span> Trans-Neptunian object

    2014 PN70 (internally designated g12000JZ, g1 and PT3) is a trans-Neptunian object from the cold classical Kuiper belt located in the outermost region of the Solar System. It measures approximately 40 kilometers (25 miles) in diameter. The object was first observed by the New Horizons Search Team using the Hubble Space Telescope on 6 August 2014, and was a proposed flyby target for the New Horizons probe until 2015, when the alternative target 486958 Arrokoth was selected.

    (533560) 2014 JM80, provisional designation 2014 JM80, is a trans-Neptunian object from the scattered disc in the outermost Solar System, approximately 340 kilometers (210 miles) in diameter. It was discovered on 9 May 2010 by astronomers with the Pan-STARRS-1 survey at the Haleakala Observatory, Hawaii, in the United States. According to American astronomer Michael Brown, it is "possibly" a dwarf planet.

    <span class="nowrap">2017 OF<sub>69</sub></span>

    2017 OF69 is a resonant trans-Neptunian object from the Kuiper belt, located in the outermost region of the Solar System in the Kuiper belt's plutino population and measures approximately 533 kilometers (330 miles) in diameter. It was first observed on 26 July 2017, by American astronomers David Tholen, Scott Sheppard, and Chad Trujillo at Mauna Kea Observatories in Hawaii, but not announced until 31 May 2018 due to observations made in April and May 2018 refining its orbit significantly.

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    <span class="nowrap">2012 HE<sub>85</sub></span>

    2012 HE85 is a small, resonant trans-Neptunian object from the Kuiper belt, located in the outermost region of the Solar System, approximately 74 kilometers (46 miles) in diameter. It was first observed by a team of astronomers using one of the Magellan Telescopes in Chile during the New Horizons KBO Search on 18 April 2012, in order to find a potential flyby target for the New Horizons spacecraft. The likely 5:9 resonant object was imaged by the spacecraft from afar at a record distance from Earth in 2017.

    2011 JY31 is a binary trans-Neptunian object from the Kuiper belt, located in the outermost region of the Solar System. It is a cold classical Kuiper belt object. 2011 JY31 was discovered on 4 May 2011, by a team of astronomers using one of the Magellan Telescopes in Chile during the New Horizons KBO Search for a potential flyby target for the New Horizons spacecraft. Distant observations by New Horizons from September 2018 revealed its binary nature, showing two 68 km (42 mi)-wide components in a tight, mutual orbit 200 km (120 mi) apart.

    References

    1. 1 2 3 4 5 6 7 "516977 (2012 HZ84)". Minor Planet Center. Retrieved 5 January 2019.
    2. 1 2 3 4 5 6 "JPL Small-Body Database Browser: 516977 (2012 HZ84)" (2017-06-23 last obs.). Jet Propulsion Laboratory . Retrieved 5 January 2019.
    3. 1 2 "Orbit Fit and Astrometric record for 516977". Southwest Research Institute . Retrieved 5 January 2019.
    4. 1 2 3 4 Johnston, Wm. Robert (7 October 2018). "List of Known Trans-Neptunian Objects". Johnston's Archive. Retrieved 5 January 2019.
    5. 1 2 3 "New Horizons Captures Record-Breaking Images in the Kuiper Belt". NASA. 8 February 2018. Retrieved 5 January 2019.
    6. Buie, M. W.; Parker, A. H.; Tholen, D. J.; Borncamp, D. M.; Osip, D. J.; Schechter, P. L.; et al. (11 March 2014). "2012 HZ84". Minor Planet Electronic Circular . 2014-E67 (2014-E67 (2014)). Bibcode:2014MPEC....E...67B . Retrieved 5 January 2019.
    7. Wall, Mike (4 January 2019). "The Hunt Is On for Moons Around Ultima Thule". Space.com . Retrieved 5 January 2019.
    8. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 January 2019.