Gaia Data Release 3

Reflectance spectra of Solar System small bodies^⋆

¹ Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Bd de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
² Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA UK
³ Royal Observatory of Belgium, Ringlaan 3, 1180 Brussels, Belgium
⁴ INAF – Osservatorio Astrofisico di Torino, Via Osservatorio 20, 10025 Pino Torinese, TO, Italy
⁵ Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
⁶ Department of Physics, University of Helsinki, PO Box 64, 00014 Helsinki, Finland
⁷ Finnish Geospatial Research Institute FGI, Geodeetinrinne 2, 02430 Masala, Finland
⁸ Astronomisches Rechen-Institut, Zentrum fr Astronomie der Universitt Heidelberg, Mnchhofstr. 12-14, 69120 Heidelberg, Germany
⁹ INAF – Osservatorio astronomico di Padova, Vicolo Osservatorio 5, 35122 Padova, Italy
¹⁰ European Space Agency (ESA), European Space Research and Technology Centre (ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
¹¹ GEPI, Observatoire de Paris, Université PSL, CNRS, 5 Place Jules Janssen, 92190 Meudon, France
¹² Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
¹³ Laboratoire d’astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615 Pessac, France
¹⁴ Department of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, Switzerland
¹⁵ European Space Agency (ESA), European Space Astronomy Centre (ESAC), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
¹⁶ Aurora Technology for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
¹⁷ Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, 08028 Barcelona, Spain
¹⁸ Lohrmann Observatory, Technische Universitt Dresden, Mommsenstraße 13, 01062 Dresden, Germany
¹⁹ Lund Observatory, Department of Astronomy and Theoretical Physics, Lund University, Box 43, 22100 Lund, Sweden
²⁰ CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
²¹ Institut d’Astronomie et d’Astrophysique, Université Libre de Bruxelles CP 226, Boulevard du Triomphe, 1050 Brussels, Belgium
²² F.R.S.-FNRS, Rue d’Egmont 5, 1000 Brussels, Belgium
²³ INAF – Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy
²⁴ Max Planck Institute for Astronomy, Knigstuhl 17, 69117 Heidelberg, Germany
²⁵ European Space Agency (ESA), Noordwijk, The Netherlands
²⁶ University of Turin, Department of Physics, Via Pietro Giuria 1, 10125 Torino, Italy
²⁷ INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna, Via Piero Gobetti 93/3, 40129 Bologna, Italy
²⁸ DAPCOM for Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB), Martí i Franquès 1, 08028 Barcelona, Spain
²⁹ Observational Astrophysics, Division of Astronomy and Space Physics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
³⁰ ALTEC S.p.a, Corso Marche, 79, 10146 Torino, Italy
³¹ Sednai Sàrl, Geneva, Switzerland
³² Department of Astronomy, University of Geneva, Chemin d’Ecogia 16, 1290 Versoix, Switzerland
³³ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey, RH5 6NT UK
³⁴ Gaia DPAC Project Office, ESAC, Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
³⁵ Telespazio UK S.L. for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
³⁶ SYRTE, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, LNE, 61 avenue de l’Observatoire, 75014 Paris, France
³⁷ National Observatory of Athens, I. Metaxa and Vas. Pavlou, Palaia Penteli, 15236 Athens, Greece
³⁸ IMCCE, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Univ. Lille, 77 av. Denfert-Rochereau, 75014 Paris, France
³⁹ Serco Gestión de Negocios for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
⁴⁰ Institut d’Astrophysique et de Géophysique, Université de Liège, 19c, Allée du 6 Août, 4000 Liège, Belgium
⁴¹ CRAAG – Centre de Recherche en Astronomie, Astrophysique et Géophysique, Route de l’Observatoire Bp 63 Bouzareah, 16340 Algiers, Algeria
⁴² Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ UK
⁴³ RHEA for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
⁴⁴ ATG Europe for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
⁴⁵ CIGUS CITIC – Department of Computer Science and Information Technologies, University of A Coruña, Campus de Elviña s/n, A Coruña, 15071 Spain
⁴⁶ Université de Strasbourg, CNRS, Observatoire astronomique de Strasbourg, UMR 7550, 11 rue de l’Université, 67000 Strasbourg, France
⁴⁷ Kavli Institute for Cosmology Cambridge, Institute of Astronomy, Madingley Road, Cambridge, CB3 0HA UK
⁴⁸ Leibniz Institute for Astrophysics Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam, Germany
⁴⁹ CENTRA, Faculdade de Ciências, Universidade de Lisboa, Edif. C8, Campo Grande, 1749-016 Lisboa, Portugal
⁵⁰ Department of Informatics, Donald Bren School of Information and Computer Sciences, University of California, Irvine, 5226 Donald Bren Hall, 92697-3440 CA, Irvine, USA
⁵¹ INAF – Osservatorio Astrofisico di Catania, Via S. Sofia 78, 95123 Catania, Italy
⁵² Dipartimento di Fisica e Astronomia “Ettore Majorana”, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy
⁵³ INAF – Osservatorio Astronomico di Roma, Via Frascati 33, 00078 Monte Porzio Catone, Roma, Italy
⁵⁴ Space Science Data Center – ASI, Via del Politecnico SNC, 00133 Roma, Italy
⁵⁵ Institut UTINAM CNRS UMR6213, Université Bourgogne Franche-Comté, OSU THETA Franche-Comté Bourgogne, Observatoire de Besançon, BP1615, 25010 Besançon Cedex, France
⁵⁶ HE Space Operations BV for European Space Agency (ESA), Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
⁵⁷ Dpto. de Inteligencia Artificial, UNED, c/ Juan del Rosal 16, 28040 Madrid, Spain
⁵⁸ Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Etvs Loránd Research Network (ELKH), MTA Centre of Excellence, Konkoly Thege Miklós út 15-17, 1121 Budapest, Hungary
⁵⁹ ELTE Etvs Loránd University, Institute of Physics, 1117 Pázmány Péter sétány 1A, Budapest, Hungary
⁶⁰ Instituut voor Sterrenkunde, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
⁶¹ Department of Astrophysics/IMAPP, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
⁶² University of Vienna, Department of Astrophysics, Trkenschanzstraße 17, 1180 Vienna, Austria
⁶³ Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, 1290 Versoix, Switzerland
⁶⁴ Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen, The Netherlands
⁶⁵ School of Physics and Astronomy/Space Park Leicester, University of Leicester, University Road, Leicester, LE1 7RH UK
⁶⁶ Thales Services for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
⁶⁷ Depto. Estadística e Investigación Operativa. Universidad de Cádiz, Avda. República Saharaui s/n, 11510 Puerto Real, Cádiz, Spain
⁶⁸ Center for Research and Exploration in Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, USA
⁶⁹ GSFC – Goddard Space Flight Center, Code 698, 8800 Greenbelt Rd, 20771 MD, Greenbelt, USA
⁷⁰ EURIX S.r.l., Corso Vittorio Emanuele II 61, 10128 Torino, Italy
⁷¹ Porter School of the Environment and Earth Sciences, Tel Aviv University, Tel Aviv, 6997801 Israel
⁷² Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS 15, Cambridge, MA, 02138 USA
⁷³ HE Space Operations BV for European Space Agency (ESA), Camino bajo del Castillo, s/n, Urbanizacion Villafranca del Castillo, Villanueva de la Cañada, 28692 Madrid, Spain
⁷⁴ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
⁷⁵ LFCA/DAS,Universidad de Chile, CNRS, Casilla 36-D, Santiago, Chile
⁷⁶ SISSA – Scuola Internazionale Superiore di Studi Avanzati, Via Bonomea 265, 34136 Trieste, Italy
⁷⁷ Telespazio for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
⁷⁸ University of Turin, Department of Computer Sciences, Corso Svizzera 185, 10149 Torino, Italy
⁷⁹ Dpto. de Matemática Aplicada y Ciencias de la Computación, Univ. de Cantabria, ETS Ingenieros de Caminos, Canales y Puertos, Avda. de los Castros s/n, 39005 Santander, Spain
⁸⁰ Centro de Astronomía – CITEVA, Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, 1270300 Chile
⁸¹ DLR Gesellschaft für Raumfahrtanwendungen (GfR), mbH Mnchener Straße 20, 82234 Weßling, Germany
⁸² Centre for Astrophysics Research, University of Hertfordshire, College Lane, AL10 9AB Hatfield, UK
⁸³ University of Turin, Mathematical Department “G.Peano”, Via Carlo Alberto 10, 10123 Torino, Italy
⁸⁴ INAF – Osservatorio Astronomico d’Abruzzo, Via Mentore Maggini, 64100 Teramo, Italy
⁸⁵ Instituto de Astronomia, Geofìsica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão, 1226, Cidade Universitaria, 05508-900 São Paulo, SP, Brazil
⁸⁶ APAVE SUDEUROPE SAS for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
⁸⁷ Mésocentre de calcul de Franche-Comté, Université de Franche-Comté, 16 route de Gray, 25030 Besançon Cedex, France
⁸⁸ ATOS for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
⁸⁹ School of Physics and Astronomy, Tel Aviv University, Tel Aviv, 6997801 Israel
⁹⁰ Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, Belfast, BT7 1NN UK
⁹¹ Centre de Données Astronomique de Strasbourg, Strasbourg, France
⁹² Institute for Computational Cosmology, Department of Physics, Durham University, Durham, DH1 3LE UK
⁹³ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
⁹⁴ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching, Germany
⁹⁵ Data Science and Big Data Lab, Pablo de Olavide University, 41013 Seville, Spain
⁹⁶ Barcelona Supercomputing Center (BSC), Plaça Eusebi Gell 1-3, 08034 Barcelona, Spain
⁹⁷ ETSE Telecomunicación, Universidade de Vigo, Campus Lagoas-Marcosende, 36310 Vigo, Galicia, Spain
⁹⁸ Asteroid Engineering Laboratory, Space Systems, Luleå University of Technology, Box 848, 981 28 Kiruna, Sweden
⁹⁹ Vera C Rubin Observatory, 950 N. Cherry Avenue, Tucson, AZ, 85719 USA
¹⁰⁰ Department of Astrophysics, Astronomy and Mechanics, National and Kapodistrian University of Athens, Panepistimiopolis, Zografos, 15783 Athens, Greece
¹⁰¹ TRUMPF Photonic Components GmbH, Lise-Meitner-Straße 13, 89081 Ulm, Germany
¹⁰² IAC – Instituto de Astrofisica de Canarias, Via Láctea s/n, 38200 La Laguna S.C., Tenerife, Spain
¹⁰³ Department of Astrophysics, University of La Laguna, Via Láctea s/n, 38200 La Laguna S.C., Tenerife, Spain
¹⁰⁴ Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS Delft, The Netherlands
¹⁰⁵ Radagast Solutions, Simon Vestdijkpad 24, 2321WD Leiden, The Netherlands
¹⁰⁶ Laboratoire Univers et Particules de Montpellier, CNRS Université Montpellier, Place Eugène Bataillon, CC72, 34095 Montpellier Cedex 05, France
¹⁰⁷ Université de Caen Normandie, Côte de Nacre Boulevard Maréchal Juin, 14032 Caen, France
¹⁰⁸ LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université de Paris, 5 Place Jules Janssen, 92190 Meudon, France
¹⁰⁹ SRON Netherlands Institute for Space Research, Niels Bohrweg 4, 2333 CA Leiden, The Netherlands
¹¹⁰ Astronomical Observatory, University of Warsaw, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
¹¹¹ Scalian for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9, France
¹¹² Université Rennes, CNRS, IPR (Institut de Physique de Rennes), UMR 6251, 35000 Rennes, France
¹¹³ INAF – Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy
¹¹⁴ Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030 PR China
¹¹⁵ University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049 PR China
¹¹⁶ Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark
¹¹⁷ DXC Technology, Retortvej 8, 2500 Valby, Denmark
¹¹⁸ Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA, 93117 USA
¹¹⁹ CIGUS CITIC, Department of Nautical Sciences and Marine Engineering, University of A Coruña, Paseo de Ronda 51, 15071 A Coruña, Spain
¹²⁰ Astrophysics Research Institute, Liverpool John Moores University, 146 Brownlow Hill, Liverpool, L3 5RF UK
¹²¹ IPAC, Mail Code 100-22, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA, 91125 USA
¹²² IRAP, Université de Toulouse, CNRS, UPS, CNES, 9 Av. colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
¹²³ MTA CSFK Lendlet Near-Field Cosmology Research Group, Konkoly Observatory, MTA Research Centre for Astronomy and Earth Sciences, Konkoly Thege Miklós út 15-17, 1121 Budapest, Hungary
¹²⁴ Departmento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, 28040 Madrid, Spain
¹²⁵ Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
¹²⁶ Villanova University, Department of Astrophysics and Planetary Science, 800 E Lancaster Avenue, Villanova, PA, 19085 USA
¹²⁷ INAF – Osservatorio Astronomico di Brera, Via E. Bianchi, 46, 23807 Merate, LC, Italy
¹²⁸ STFC, Rutherford Appleton Laboratory, Harwell, Didcot, OX11 0QX UK
¹²⁹ Charles University, Faculty of Mathematics and Physics, Astronomical Institute of Charles University, V Holesovickach 2, 18000 Prague, Czech Republic
¹³⁰ Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, 7610001 Israel
¹³¹ Department of Astrophysical Sciences, 4 Ivy Lane, Princeton University, Princeton, NJ, 08544 USA
¹³² Departamento de Astrofísica, Centro de Astrobiología (CSIC-INTA), ESA-ESAC. Camino Bajo del Castillo s/n., 28692 Villanueva de la Cañada, Madrid, Spain
¹³³ naXys, University of Namur, Rempart de la Vierge, 5000 Namur, Belgium
¹³⁴ CGI Deutschland B.V. & Co. KG, Mornewegstr. 30, 64293 Darmstadt, Germany
¹³⁵ Institute of Global Health, University of Geneva, Geneva, Switzerland
¹³⁶ Astronomical Observatory Institute, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland
¹³⁷ H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL UK
¹³⁸ Department of Physics and Astronomy G. Galilei, University of Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
¹³⁹ CERN, Esplanade des Particules 1, PO Box 1211 Geneva, Switzerland
¹⁴⁰ Applied Physics Department, Universidade de Vigo, 36310 Vigo, Spain
¹⁴¹ Association of Universities for Research in Astronomy, 1331 Pennsylvania Ave. NW, Washington, DC, 20004 USA
¹⁴² European Southern Observatory, Alonso de Córdova 3107, Casilla 19, Santiago, Chile
¹⁴³ Sorbonne Université, CNRS, UMR7095, Institut d’Astrophysique de Paris, 98bis bd. Arago, 75014 Paris, France
¹⁴⁴ Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, 1000 Ljubljana, Slovenia

Received: 14 April 2022
Accepted: 30 May 2022

Abstract

Context. The Gaia mission of the European Space Agency (ESA) has been routinely observing Solar System objects (SSOs) since the beginning of its operations in August 2014. The Gaia data release three (DR3) includes, for the first time, the mean reflectance spectra of a selected sample of 60 518 SSOs, primarily asteroids, observed between August 5, 2014, and May 28, 2017. Each reflectance spectrum was derived from measurements obtained by means of the Blue and Red photometers (BP/RP), which were binned in 16 discrete wavelength bands. For every spectrum, the DR3 also contains additional information about the data quality for each band.

Aims. We describe the processing of the Gaia spectral data of SSOs, explaining both the criteria used to select the subset of asteroid spectra published in Gaia DR3, and the different steps of our internal validation procedures. In order to further assess the quality of Gaia SSO reflectance spectra, we carried out external validation against SSO reflectance spectra obtained from ground-based and space-borne telescopes and available in the literature; we present our validation approach.

Methods. For each selected SSO, an epoch reflectance was computed by dividing the calibrated spectrum observed by the BP/RP at each transit on the focal plane by the mean spectrum of a solar analogue. The latter was obtained by averaging the Gaia spectral measurements of a selected sample of stars known to have very similar spectra to that of the Sun. Finally, a mean of the epoch reflectance spectra was calculated in 16 spectral bands for each SSO.

Results.Gaia SSO reflectance spectra are in general agreement with those obtained from a ground-based spectroscopic campaign specifically designed to cover the same spectral interval as Gaia and mimic the illumination and observing geometry characterising Gaia SSO observations. In addition, the agreement between Gaia mean reflectance spectra and those available in the literature is good for bright SSOs, regardless of their taxonomic spectral class. We identify an increase in the spectral slope of S-type SSOs with increasing phase angle. Moreover, we show that the spectral slope increases and the depth of the 1 μm absorption band decreases for increasing ages of S-type asteroid families. The latter can be interpreted as proof of progressive ageing of S-type asteroid surfaces due to their exposure to space weathering effects.