Bibcode
de Leon, Julia; Campins, H.; Tsiganis, K.; Morbidelli, A.; Licandro, J.
Bibliographical reference
American Astronomical Society, DPS meeting #42, #13.27; Bulletin of the American Astronomical Society, Vol. 42, p.1058
Advertised on:
10
2010
Citations
2
Refereed citations
2
Description
Asteroid (3200) Phaethon is a remarkable Near Earth Asteroid (NEA). It
was the first asteroid associated with a meteor shower, namely the
Geminid stream1. Phaethon's unusual orbit has a
high inclination and a very low perihelion distance (0.14 AU). Its
reflectance spectrum suggests a connection with primitive meteorites,
best fitting with CI/CM carbonaceous chondrites2, aqueously
altered and rich in hydrated silicates. However, its origin is not well
determined. Recent studies suggest a connection with the population of
main-belt comets3, classifying Phaethon as an activated
asteroid. Here we show that the most likely source of Phaethon and the
Geminids is the asteroid (2) Pallas, one of the largest asteroids in the
main belt, which is surrounded by a collisional family, containing
several Phaethon-sized objects. Pallas’ highly inclined orbit and
surface composition, also primitive and with evidence of
hydration4, support this connection. Our analysis reveals a
striking similarity between Phaethon's visual spectrum and those of
Pallas family members. Moreover, our numerical simulations show the
existence of a robust dynamical pathway, connecting the orbital
neighborhood of Pallas with that of Phaethon. In this respect, the
Pallas family may constitute a source of primitive NEAs. (The author
gratefully acknowledges support from the Spanish "Ministerio de Ciencia
e Innovación" projects AYA2005-07808-C03-02 and
AYA2008-06202-C03-02.)
References
1. Whipple, F. L. 1983, IAU Circular, 3881
2. Licandro, J., Campins, H., Mothe-Diniz, T., Pinilla-Alonso, N. &
de Leon, J. 2007, Astron. Astrophys. 461, 751-757
3. Hsieh, H. H., & Jewitt, D. 2006, Science, 312, 561-563
4. Rivkin, A. S., Howell, E. S., Vilas, F. & Lebofsky, L. A. in
Asteroids III (eds Bottke, W. F., Cellino, A., Paolicchi, P. &
Binzel, R. P.) 235-253 (Univ. Arizona Press, 2002).