Context. The Hayabusa2 mission, which will be launched by JAXA in 2014, will return samples from the C-type near-Earth asteroid (162173) 1999 JU3. To better plan the mission, it is important to obtain as many physical characteristics of the asteroid as possible from ground-based observations. Moreover, these can then be calibrated with the in-situ and laboratory studies and be used to better understand other similar objects. Regarding the surface composition of the target asteroid, previous spectroscopic studies in the visible provided conflicting results for the possible presence of a deep absorption band, which is usually related to aqueous alteration processes. Aims. Our goal is to better understand the surface composition of asteroid (162173) 1999 JU3, and how it relates to the spectral differences observed by diverse authors at different epochs and telescopes. Moreover, to support the JAXA mission planning, we aim to constrain the level of aqueous alteration and thermal activity undergone by the object. Methods. The adopted methodology was to observe different regions of the surface of the asteroid that rotates around its axis. Spectroscopic observations that cover about 70% of its surface were therefore obtained at the SOAR telescope in Chile on 2012 July 9−10. Results. Our results indicate that the surface of asteroid (162173) 1999 JU3 presents featureless spectra with very little variation. Conclusions. No sign of an absorption feature that could be related to aqueous alteration processes is detectable in the observed spectra.

Context. To take advantage of the large dataset provided by the SDSS data, recently a new taxonomic scheme was proposed designed to be compatible with previous taxonomies. One interesting feature in this distribution is the large number of Q p asteroids scattered all around the main belt with a marked concentration in the Vesta region, where the V p are found most frequently. Since the mineralogy and thermal evolution traditionally related to the classical Q-and V-type taxonomic classes (and by construction the Q p and V p ), this finding was quite surprising. Aims. We aim to observationally determine the mineralogy of a sample of Q p asteroids of and outside the Vesta family to test whether the Q p of the Vesta family are indeed basaltic, and whether the difference in band depth implied by the SDSS spectra relates to diffences in mineralogy with respect to the V p . Moreover, we aim to determine whether the Q p outside Vesta family have an ordinary chondrite (OC) mineralogy and whether their spectra indeed correspond to Q-class asteroids. Methods. We observed a sample of asteroids classified as Q p -type in the literature, mainly located in the Vesta family and neighborhood, to confirm their mineralogy. Spectroscopic observations of 11 asteroids were obtained at the SOAR and IRTF telescopes in the visible and near-infrared region. Thermal observations of three objects were also carried out at the Gemini South telescope in order to determine the albedo of the asteroids. Results. The analysis indicated that all observed asteroids in the Vesta vicinity have a basalt-rich mineralogy, with no clear difference from other Vesta family members in terms of silicate composition. From our study it is not clear why these particular basaltic asteroids have a relatively suppressed band I so that they are classified as Q p . Two asteroids with an OC-compatible mineralogy were identified in the external part of the main belt, at around 2.8−2.9 AU. This discovery suggests new dynamical routes for the transport of Q-type asteroids to the near-Earth region and of OC meteorites to the Earth.

The distribution of professional observatories around the world is quite biased toward the Northern Hemisphere, and this tendency is even more pronounced when considering those dedicated only to the study of small solar system bodies. In the Southern Hemisphere, the IMPACTON project deployed the Observatório Astronômico do Sertão de Itaparica (OASI), dedicated to the observation of minor bodies of the solar system with emphasis on Near-Earth Objects (NEOs). The observatory is located at the county of Itacuruba, in the Pernambuco State of Brazil, and operate a 1 m Cassegrain telescope. Here, we present a complete characterization of the OASI instruments and the sky conditions during the first eight years of operations. The limiting magnitudes are determined in the different available filters. The median seeing results to be 1 22, with a higher number of photometric nights from April to October. We also give an overview of the results obtained from the OASI observations and discuss them in the light of similar data from the literature. In particular, the rotational periods of 23 NEOs, and the spin directions and shapes of 9 NEOs, have been determined for the very first time using our observations. Analyzing rotational periods, sizes and taxonomic classification from the literature and OASI, we conclude that the fast rotating NEOs are predominantly S-type objects. However, rotational periods obtained at the OASI and with similar value from LCDB database allowed to identify the first fast rotator C-type NEO: asteroid 436724. With an estimated tensile strength as low as 0.5 KPa, this asteroid allows us to suggest that it defines the border between the C-and S-type fast rotators in the size versus period diagram. Although this hypothesis is based on a very small sample it is compatible with all presently available data. Only new observations, however, can prove if this hypothesis is correct.