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@InProceedings{WinterAraśMaca:2017:ClNETh,
               author = "Winter, O. C. and Ara{\'u}jo, R. A. N. and Macau, Elbert Einstein 
                         Nehrer",
          affiliation = "{Universidade Estadual Paulista (UNESP)} and {Universidade 
                         Estadual Paulista (UNESP)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Classification of NEAs through dynamical evolution",
                 year = "2017",
         organization = "Asteroids, Comets, Meteors",
             abstract = "Introduction: The near Earth asteroids (NEAs) are usually 
                         classified according to their orbital characteristics into four 
                         groups: Aten, Apollo, Amor and Atira. An Aten has a semi-major 
                         axis of less than 1 au and aphelion distance greater than the 
                         Earth's perihelion distance. An Amor has perihelion distance 
                         greater than the Earth's aphelion distance and aphelion smaller 
                         than 1.3 au. An Apollo has semi-major axis of more than 1 au and 
                         perihelion distance smaller than the Earth's aphelion distance. An 
                         Atira has aphelion distance smaller than Earth's perihelion 
                         distance. However, this is a static classification, based on their 
                         current osculating orbital elements. The NEAs live in a region 
                         highly perturbed by the terrestrial planets. In general, their 
                         lifetime is of the order of 10 Myrs. Most of them cross the border 
                         from one group to another during their lifetime, that means they 
                         temporarily belong to a given group. So, the question is how would 
                         they be classified according to their dynamical orbital evolution? 
                         Approach: In the present work is studied the temporal orbital 
                         evolution of the NEAs. There were performed numerical simulations 
                         of a representative sample of NEAs under the gravitational 
                         influence of all planets and the Sun. Their dynamics is dominated 
                         by the gravitational interactions with the terrestrial planets. A 
                         single close encounter with one of this planets can move an 
                         asteroid from one group to another. We pay special attention to 
                         their mobility as a function of their initial location in the 
                         semi-major axis versus eccentricity plane (a x e), and 
                         consequently in their transition between the groups. Results: A 
                         general view of the results can be seen in Figure 1. T The coded 
                         color indicates the states, i.e, to how many groups a NEA belonged 
                         to along its lifetime. A representative example is the following. 
                         We found two Apollo asteroids with very distinct dynamical 
                         behaviors. One of them explores a wide region of the space 
                         covering all the groups (from the inner Atira up to the outer 
                         Asteroid Main Belt) (Figure 2), while the other asteroid remains 
                         its entire lifetime in a narrow region, jumping from Apollo to 
                         Atens and vice-versa. The results reveal some sort of patterns to 
                         be used in a new classification of the NEAs in terms of dynamical 
                         orbital evolution.",
  conference-location = "Montevideo, Uruguay",
      conference-year = "10-14 Apr.",
             language = "en",
        urlaccessdate = "30 nov. 2020"
}


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