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28-459: (Redirected from PT-2 ) PT2 or its variants may refer to: New Horizons PT2 aka 2014 OS393 Pratt & Whitney PT2 company designation for the Pratt & Whitney T34 turboprop aircraft engine PT-2 , a pre-World War II US Navy PT-boat. Prison Tycoon 2: Maximum Security (2006 videogame) PT2 a paratriathlon classification Pt. 2 ,

56-580: A 2016 single by Kanye West See also [ edit ] Part Two (disambiguation) [REDACTED] Topics referred to by the same term This disambiguation page lists articles associated with the same title formed as a letter–number combination. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=PT2&oldid=1258615613 " Category : Letter–number combination disambiguation pages Hidden categories: Short description

84-498: A classical KBO if: An alternative classification, introduced by B. Gladman , B. Marsden and C. van Laerhoven in 2007, uses a 10-million-year orbit integration instead of the Tisserand's parameter. Classical objects are defined as not resonant and not being currently scattered by Neptune. Formally, this definition includes as classical all objects with their current orbits that Unlike other schemes, this definition includes

112-805: A fairly reliable orbit. 2014 OS 393 was discovered by the New Horizons Search Team with the help of the Hubble Space Telescope because the object has a magnitude of 26.3, which is too faint to be observed by ground-based telescopes. Preliminary observations by the HST searching for KBO flyby targets for the New Horizons probe started in June 2014, and more intensive observations continued in July and August. 2014 OS 393

140-465: A few resolved New Horizons images, but in 2020 this remained inconclusive. Later work by Hal Weaver in 2021 showed that 2014 OS 393 is indeed a binary, with two components about 30 km (19 mi) in diameter, about 150 km (93 mi) apart. After the New Horizons probe completed its flyby of Pluto , the probe was to be maneuvered to a flyby of at least one Kuiper belt object. Several potential targets were under consideration for

168-671: A high uncertainty of 7. The body's observation arc begins with a precovery taken on 25 June 2014, by the New Horizons KBO Search team using the Subaru Telescope at Mauna Kea Observatory on Hawaii. and ends presently on 21 July 2017, covering 1122 days. After the New Horizons probe completed its flyby of Arrokoth, the probe began observations of other nearby surrounding Kuiper belt objects, including 2014 OS 393 . Observations of 2014 OS 393 's brightness variations at high phase angles allowed

196-497: A preference for the middle of the main belt; arguably, smaller objects close to the limiting resonances have been either captured into resonance or have their orbits modified by Neptune. The 'hot' and 'cold' populations are strikingly different: more than 30% of all cubewanos are in low inclination, near-circular orbits. The parameters of the plutinos’ orbits are more evenly distributed, with a local maximum in moderate eccentricities in 0.15–0.2 range, and low inclinations 5–10°. See also

224-497: Is a trans-Neptunian object and likely a non-resonant classical Kuiper belt object , also known as "cubewano". It orbits the Sun at a distance of 43.3–44.84  AU once every 292 years ( semi-major axis of 44.04 AU). Its orbit has an eccentricity of 0.018 and an inclination of 3.8 ° with respect to the ecliptic . As this object has not been observed since July 2017, its orbit remains rather poorly determined still containing

252-635: Is characterised by highly inclined, more eccentric orbits. The terms 'hot' and 'cold' has nothing to do with surface or internal temperatures, but rather refer to the orbits of the objects, by analogy to molecules in a gas, which increase their relative velocity as they heat up. The Deep Ecliptic Survey reports the distributions of the two populations; one with the inclination centered at 4.6° (named Core ) and another with inclinations extending beyond 30° ( Halo ). The vast majority of KBOs (more than two-thirds) have inclinations of less than 5° and eccentricities of less than 0.1 . Their semi-major axes show

280-573: Is different from Wikidata All article disambiguation pages All disambiguation pages New Horizons PT2 2014 OS 393 , unofficially designated e31007AI , e3 and PT2 , is a binary trans-Neptunian object in the classical Kuiper belt , the outermost region of the Solar System . It was first observed by the New Horizons KBO Search using the Hubble Space Telescope on 30 July 2014. Until 2015, when

308-685: The Deep Ecliptic Survey (DES) do not list cubewanos (classical objects) using the same criteria. Many TNOs classified as cubewanos by the MPC, such as dwarf planet Makemake , are classified as ScatNear (possibly scattered by Neptune) by the DES. (119951) 2002 KX 14 may be an inner cubewano near the plutinos . Furthermore, there is evidence that the Kuiper belt has an 'edge', in that an apparent lack of low-inclination objects beyond 47–49 AU

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336-556: The Haumea family . It includes Haumea, its moons, 2002 TX 300 and seven smaller bodies. The objects not only follow similar orbits but also share similar physical characteristics. Unlike many other KBO their surface contains large amounts of water ice (H 2 O) and no or very little tholins . The surface composition is inferred from their neutral (as opposed to red) colour and deep absorption at 1.5 and 2. μm in infrared spectrum . Several other collisional families might reside in

364-409: The New Horizons probe to make a rough determination of its rotation period as well as its shape. As New Horizons observed 2014 OS 393 at phase angles near 90°, it displayed large variations in brightness, indicating that its shape is either extremely elongated or 2014 OS 393 could be a binary system of two separated components. 2014 OS 393 appeared to be possibly a separated binary in

392-435: The scattered disk remains blurred. As of 2023 , there are 870 objects with perihelion (q) > 40 AU and aphelion (Q) < 48 AU. Introduced by the report from the Deep Ecliptic Survey by J. L. Elliott et al. in 2005 uses formal criteria based on the mean orbital parameters. Put informally, the definition includes the objects that have never crossed the orbit of Neptune. According to this definition, an object qualifies as

420-423: The 1:2 resonance. 50000 Quaoar , for example, has a near-circular orbit close to the ecliptic . Plutinos, on the other hand, have more eccentric orbits bringing some of them closer to the Sun than Neptune . The majority of classical objects, the so-called cold population , have low inclinations (< 5 ° ) and near-circular orbits, lying between 42 and 47 AU. A smaller population (the hot population )

448-524: The classical Kuiper belt. As of January 2019, only one classical Kuiper belt object has been observed up close by spacecraft. Both Voyager spacecraft have passed through the region before the discovery of the Kuiper belt. New Horizons was the first mission to visit a classical KBO. After its successful exploration of the Pluto system in 2015, the NASA spacecraft has visited the small KBO 486958 Arrokoth at

476-511: The cold and hot populations and confirm the distinction between the homogenous red cold population and the bluish hot population. Another difference between the low-inclination (cold) and high-inclination (hot) classical objects is the observed number of binary objects . Binaries are quite common on low-inclination orbits and are typically similar-brightness systems. Binaries are less common on high-inclination orbits and their components typically differ in brightness. This correlation, together with

504-466: The comparison with scattered disk objects . When the orbital eccentricities of cubewanos and plutinos are compared, it can be seen that the cubewanos form a clear 'belt' outside Neptune's orbit, whereas the plutinos approach, or even cross Neptune's orbit. When orbital inclinations are compared, 'hot' cubewanos can be easily distinguished by their higher inclinations, as the plutinos typically keep orbits below 20°. (No clear explanation currently exists for

532-523: The differences in colour, support further the suggestion that the currently observed classical objects belong to at least two different overlapping populations, with different physical properties and orbital history. There is no official definition of 'cubewano' or 'classical KBO'. However, the terms are normally used to refer to objects free from significant perturbation from Neptune, thereby excluding KBOs in orbital resonance with Neptune ( resonant trans-Neptunian objects ). The Minor Planet Center (MPC) and

560-414: The first trans-Neptunian object (TNO) found after Pluto and Charon : 15760 Albion , which until January 2018 had only the provisional designation (15760) 1992 QB 1 . Similar objects found later were often called "QB1-o's", or "cubewanos", after this object, though the term "classical" is much more frequently used in the scientific literature. Objects identified as cubewanos include: 136108 Haumea

588-404: The first such flyby. 2014 OS 393 has an estimated mean diameter between 30 and 55 kilometers, depending on the body's assumed albedo . The potential encounter in 2018–2019 would have been at a distance of 43–44  AU from the Sun. On 28 August 2015, the New Horizons team announced the selection of 2014 MU 69 (later named 486958 Arrokoth ) as the next flyby target, eliminating

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616-425: The inclinations of 'hot' cubewanos. ) In addition to the distinct orbital characteristics, the two populations display different physical characteristics. The difference in colour between the red cold population, such as 486958 Arrokoth , and more heterogeneous hot population was observed as early as in 2002. Recent studies, based on a larger data set, indicate the cut-off inclination of 12° (instead of 5°) between

644-554: The object 486958 Arrokoth was selected, it was a potential flyby target for the New Horizons probe. Estimated to be approximately 42 kilometres (26 mi) in diameter, the object had a poorly determined orbit as it had been observed for only a few months. With MPEC 2024-E99 the Minor Planet Center published on 6 March 2024 additional observations by New Horizons KBO Search-Subaru which allowed to compute

672-407: The objects with major semi-axis less than 39.4 AU (2:3 resonance)—termed inner classical belt , or more than 48.7 (1:2 resonance) – termed outer classical belt , and reserves the term main classical belt for the orbits between these two resonances. The first known collisional family in the classical Kuiper belt—a group of objects thought to be remnants from the breakup of a single body—is

700-608: The other possible targets — 2014 OS 393 , 2014 PN 70 , and 2014 MT 69 . The spacecraft passed 2014 OS 393 in January 2019, at a distance of less than 0.1 AU (15 million km, 9.3 million miles). This makes 2014 OS 393 the second closest KBO observed by New Horizons , after Arrokoth. This minor planet has not been numbered by the Minor Planet Center and remains unnamed . Classical Kuiper belt object The name "cubewano" derives from

728-470: Was first discovered in observations on July 30, 2014, but it was designated e31007AI at the time, nicknamed e3 for short. Its existence as a potential target of the New Horizons probe was revealed by NASA in October 2014 and designated PT2, but the official name 2014 OS 393 was not assigned by the Minor Planet Center until March 2015 after better orbit information was available. 2014 OS 393

756-407: Was provisionally listed as a cubewano by the Minor Planet Center in 2006, but was later found to be in a resonant orbit. There are two basic dynamical classes of classical Kuiper-belt bodies: those with relatively unperturbed ('cold') orbits, and those with markedly perturbed ('hot') orbits. Most cubewanos are found between the 2:3 orbital resonance with Neptune (populated by plutinos ) and

784-420: Was suspected as early as 1998 and shown with more data in 2001. Consequently, the traditional usage of the terms is based on the orbit's semi-major axis, and includes objects situated between the 2:3 and 1:2 resonances, that is between 39.4 and 47.8 AU (with exclusion of these resonances and the minor ones in-between). These definitions lack precision: in particular the boundary between the classical objects and

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