NEOROCKS characterization programme of near-Earth asteroids previously observed with radar&#160;
Authors: Medeiros Hissa , de León Julia , Licandro Javier , Popescu Marcel , Morate David , Pinilla-Alonso Noemi ,   Arecibo Planetary Radar Team*, and the NEOROCKS Team**
Published: September 2022

&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;&lt;strong&gt;Introduction.&lt;/strong&gt;&lt;/span&gt;&lt;span&gt; The NEO Rapid Observation, Characterization and Key Simulations (NEOROCKS) project is funded (2020-2023) through the H2020 European Commission programme to improve our knowledge on near-Earth objects by connecting expertise in performing small body astronomical observations and the related modelling needed to derive their dynamical and physical properties. The &lt;/span&gt;&lt;span&gt;&lt;em&gt;Instituto de Astrof&amp;#237;sica de Canarias&lt;/em&gt;&lt;/span&gt;&lt;span&gt; (IAC), and in particular members of the Solar System Group, participate in the NEOROCKS project and currently &lt;/span&gt;&lt;span&gt;are devoted to &lt;/span&gt;&lt;span&gt;one specific task: to collect observational data, mainly in the visible and near-infrared wavelength regions, of NEAs that have been observed in the past using the Arecibo Planetary Radar. In this work we present preliminary results, focusing on those targets &lt;/span&gt;&lt;span&gt;for which the &lt;/span&gt;&lt;span&gt;signal-to-noise &lt;/span&gt;&lt;span&gt;ratio is satisfactorily high.&lt;/span&gt;&lt;/p&gt;&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;&lt;strong&gt;Observations&lt;/strong&gt;&lt;/span&gt;&lt;span&gt;. Our observations include spectroscopy, color photometry and lightcurves. They are performed using the facilities located at the &lt;/span&gt;&lt;span&gt;&lt;em&gt;Observatorios de Canarias&lt;/em&gt;&lt;/span&gt;&lt;span&gt; (OOCC), &lt;/span&gt;&lt;span&gt;including&lt;/span&gt;&lt;span&gt; the &lt;/span&gt;&lt;span&gt;&lt;em&gt;El Teide&lt;/em&gt;&lt;/span&gt;&lt;span&gt; Observatory in the island of Tenerife and the &lt;/span&gt;&lt;span&gt;&lt;em&gt;El Roque de los Muchachos&lt;/em&gt;&lt;/span&gt;&lt;span&gt; Observatory in the island of La Palma. Visible and near-infrared spectra are mainly obtained using the 10.4-m Gran Telescopio de Canarias (GTC) and its visible (OSIRIS) and near-infrared (EMIR) spectrographs. We also use the ALFOSC spectrograph at the 2.5-m Nordic Optical Telescope (NOT). Visible color photometry is obtained using the MuSCAT2 instrument at the 1.5-m Telescopio Carlos S&amp;#225;nchez (TCS). The setup allows &lt;/span&gt;&lt;span&gt;us&lt;/span&gt;&lt;span&gt; to obtain simultaneous imaging in the &lt;/span&gt;&lt;span&gt;&lt;em&gt;g&lt;/em&gt;&lt;/span&gt;&lt;span&gt;, &lt;/span&gt;&lt;span&gt;&lt;em&gt;r&lt;/em&gt;&lt;/span&gt;&lt;span&gt;, &lt;/span&gt;&lt;span&gt;&lt;em&gt;i&lt;/em&gt;&lt;/span&gt;&lt;span&gt;, and &lt;/span&gt;&lt;span&gt;&lt;em&gt;z&lt;/em&gt;&lt;/span&gt;&lt;sub&gt;&lt;span&gt;&lt;em&gt;s&lt;/em&gt;&lt;/span&gt;&lt;/sub&gt;&lt;span&gt;&lt;em&gt; &lt;/em&gt;&lt;/span&gt;&lt;span&gt;visible bands. Time-series photometry in the visible is obtained using several telescopes, including the 46-cm TAR2, 80-cm IAC-80, and 1-m Jacobus Kapteyn Telescope (JKT). &lt;/span&gt;&lt;/p&gt;&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;&lt;strong&gt;Results&lt;/strong&gt;&lt;/span&gt;&lt;span&gt;. Spectra in the visible and/or the near-infrared wavelengths, as well as color photometry in the visible, &lt;/span&gt;&lt;span&gt;allow us&lt;/span&gt;&lt;span&gt; to taxonomically classify the targets and to infer their composition. In the case of having no albedo measurements for &lt;/span&gt;&lt;span&gt;any given&lt;/span&gt;&lt;span&gt; object, we can also use the taxonomy to have an estimation of the albedo based on the spectral class, and therefore determine the size of the asteroid. Lightcurves &lt;/span&gt;&lt;span&gt;allow us&lt;/span&gt;&lt;span&gt; to both get the asteroid rotational period and, together with radar data, to obtain the shape and the spin axis orientation of the target. In this way, a full characterization can be obtained for every asteroid observed within this program. So far, we have obtained spectra/colors/lightcurves in the visible for more than 100 NEAs. In this work, we present our most updated results. &lt;/span&gt;&lt;/p&gt;&lt;p align=&quot;justify&quot;&gt;&lt;span&gt;&lt;strong&gt;Acknowledgements&lt;/strong&gt;&lt;/span&gt;&lt;span&gt;. This project has received funding from the European Union&amp;#8217;s Horizon 2020 research and innovation programme under grant agreement No 870403.&lt;/span&gt;&lt;/p&gt;