Bibcode
Pinilla-Alonso, Noemí; de León, J.; Walsh, K. J.; Campins, H.; Lorenzi, V.; Delbo, M.; DeMeo, F.; Licandro, J.; Landsman, Z.; Lucas, M. P.; Alí-Lagoa, V.; Burt, B.
Referencia bibliográfica
Icarus, Volume 274, p. 231-248.
Fecha de publicación:
8
2016
Revista
Número de citas
26
Número de citas referidas
25
Descripción
The inner asteroid belt is an important source of near-Earth asteroids
(NEAs). Dynamical studies of the inner asteroid belt have identified
several families overlapping in proper orbital elements, including the
Polana and Eulalia families that contain a large fraction of the
low-albedo asteroids in this region.
We present results from two coordinated observational campaigns to
characterize this region through near-infrared (NIR) spectroscopy. These
campaigns ran from August 2012 to May 2014 and used the NASA Infrared
Telescope Facility and the Telescopio Nazionale Galileo. The
observations focused on objects within these families or in the
background, with low albedo (pv ≤ 0.1) and low inclination
(iP ≤ 7°). We observed 63 asteroids (57 never before
observed in the NIR): 61 low-albedo objects and two interlopers, both
compatible with S- or E- taxonomical types.
We found our sample to be spectrally homogeneous in the NIR. The sample
shows a continuum of neutral to moderately-red concave-up spectra, very
similar within the uncertainties. Only one object in the sample,
asteroid (3429) Chuvaev, has a blue spectrum, with a slope
(S‧ = - 1.33 ± 0.21%/1000 Å)
significantly different from the average spectrum (S‧ =
0.68 ± 0.68%/1000 Å). This spectral homogeneity is
independent of membership in families or the background population.
Furthermore, we show that the Eulalia and Polana families cannot be
distinguished using NIR data. We also searched for rotational
variability on the surface of (495) Eulalia which we do not detect.
(495) Eulalia shows a red concave-up spectrum with an average slope
S‧ = 0.91 ± 0.60%/1000 Å, very
similar to the average slope of our sample.
The spectra of two targets of sample-return missions, (101955) Bennu,
target of NASA's OSIRIS-Rex and (162173) 1999 JU3 target of
the Japanese Space Agency's Hayabusa-2, are very similar to our average
spectrum, which would be compatible with an origin in this region of the
inner belt.