Bibcode
Licandro, J.; de León, J.; Pinilla, N.; Serra-Ricart, M.
Bibliographical reference
Advances in Space Research, Volume 38, Issue 9, p. 1991-1994.
Advertised on:
1
2006
Journal
Citations
18
Refereed citations
14
Description
We present a preliminary analysis of visible + infrared spectra (0.5 2.4
μm) of 17 asteroids in cometary orbits (ACOs), asteroidal objects
with Tisserand parameter T < 3. These objects are part of a larger
database of ACOs observed with the Italian 3.56 m “Telescopio
Nazionale Galileo” and the 2.5 m “Nordic Optical
Telescope” at the “El Roque de los Muchachos”
Observatory (La Palma, Spain). The sample includes 3 near-Earth objects
(NEOs), objects with q ⩽ 1.3 AU, and 14 objects non-NEO ACOs
(objects with q > 1.3 AU). The spectra of the 14 non-NEO ACOs are
featureless and no low-level differences are found with respect to
normal D-type main belt asteroids. The slope distribution of these
objects is also indistinguishable from that of Hilda and Trojan
asteroids. Two of the three NEOs in cometary orbits present silicate
features typical of S and Q-type asteroids. Considering also that a
large fraction (˜30%) of the 16 NEOs in cometary orbits observed
by Binzel, R., Rivkin, A. Stuart, J., Harris, A., Bus, S., Burbine, T.
[Observed spectral properties of near-Earth objects: results for
population distribution, source regions, and space weathering processes.
Icarus, 170, 259 294, 2004] are S or Q-type, we conclude that this
suggests a different origin of the two populations.