Bibcode
Pinilla-Alonso, N.; Licandro, J.; Gil-Hutton, R.; Brunetto, R.
Referencia bibliográfica
European Planetary Science Congress 2007, Proceedings of a conference held 20-24 August, 2007 in Potsdam, Germany. Online at http://meetings.copernicus.org/epsc2007, p.694
Advertised on:
8
2007
Número de citas
0
Número de citas referidas
0
Descripción
Recent results suggest that there is a group of trans-Neptunian objects
(TNOs), 2003 EL61 being the biggest member, with similar dynamical and
physical characteristics (Brown et al. 2007, Pinilla-Alonso et al.
2007). All these objects are concentrated in a narrow region of the
orbital parameters space (41.6 < a < 43.6 AU, 25.8 < i <
28.2 deg, 0.10 < e < 0.19) which seems to suggest a common origin
for all of them. Brown et al. (2007) assert that all the objects in this
group are fragments produced by a catastrophic collision suffered by
2003 EL61. Although this scenario appears promising, it has several
problems that need to be further investigated. The spectra of these
objects show the same characteristics, they are neutral in the visible
(S0 0) and all of them present much deeper water ice absorption bands
(D >40 %) than any other TNO, except Charon. A detailed study of the
surface of (145453) 2005 RR43 (Pinilla-Alonso et al. 2007) reveals that
this small TNO is covered by almost pure water ice and scattering models
show that a significant fraction of it is in crystalline state, despite
of being one of the smallest members of the group. Furthermore the
presence of complex organics is very low (with an upper limit of 5%).
The lack of complex organics in the surface of 2005 RR43 and other
members of the group suggests a significantly smaller fraction of
carbonaceous volatiles like CH4 in this population than in "normal"
TNOs. As Pinilla-Alonso et al. (2007) suggest, such carbon-depleted
population of TNOs could be the origin of the population of
carbondepleted Jupiter family comets described by A'Hearn et al. (1995).
In this presentation we discuss the spectral characteristics of this
water ice rich group of TNOs and the possible relation between them and
the population of carbon-depleted comets.