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Using Gaia astrometry to discover asteroid companions
Coordinator
Paolo Tanga
Université Côte d'Azur, CNRS/UMR7293 Laboratoire Lagrange, Observatoire de la Côte d'Azur
Partner coordinators
Josselin Desmars
IMCCE, PSL Obs. de Paris, IPSA
Dagmara Oszkiewicz
University of Poznan (Poland)
Core tasks and team members |
Collaborators |
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Signal analysis: David Mary - Observatoire de la Côte d'Azur |
Joao Ferreira (Univ. Lisbon, Portugal) |
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Stellar occultations: Lyu Abe - Observatoire de la Côte d'Azur, B. Sicardy - Observatoire de Paris |
Rodrigo Leiva (Instituto de Astrofísica de Andalucía, Spain) |
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Physical properties: Benoit Carry - Observatoire de la Côte d'Azur |
Luana Liberato (Univ. Sao Paolo, Brasil) |
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Gaia data: Laurent Galluccio - Observatoire de la Côte d'Azur |
Katherine Minker (Obs. de la Côte d'Azur, France) |
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Alexandros Siakas (Univ. Thessaloniki, Greece) |
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Sotirios Tsavdaridis (Univ. Thessaloniki, Greece) |
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Kleomenis Tsiganis (Univ. Thessaloniki, Greece) |
Science case
GaiaMoons has the ambition to unveil a new category of binary asteroids by their signature in astrometry.
Based on Gaia and ground-based observations GaiaMoons attacks a main difficulty in asteroid studies today. The most important characteristics of asteroids that we sorely need are their densities and internal structure, which are extremely difficult to derive by means of remote-sensing techniques and are reasonably constrained for a few tens of objects.
When the absolute diameters and orbit size of a binary system can be determined, the bulk density of the two components is derived with relatively good accuracy, providing information on their internal structure.
However, a strong scientific and technical barrier is present, as our knowledge of binaries is most probably strongly biased and incomplete. This is because a whole population of binaries cannot be efficiently discovered by current techniques, involving mainly adaptive optics (high resolution) imaging (more efficient on large, relatively bright asteroids) and photometry (requiring favorable geometry and/or compact system that have different primary and secondary rotation periods).
Exploiting Gaia astrometry, GaiaMoons lifts this barrier by implementing a technique never exploited in this context, combined with more traditional approached, with the ambition to explore a population of binary asteroids that has still to be revealed.
Method
Analysis of asteroid astrometryWe exploit asteroid astrometry obtained by the Gaia mission of the European Space Agency. From the orbital fit, we derive from the residuals the possible signatures of the presence of a companion. This first step produces a list of candidate binary asteroids. |
Physical validation of the candidatesThe candidates must be analysed to check if the presence of a satellite is consistent with the supposed physical properties of the asteroid (size, density...). Candidates that are not compatibles are discarded. |
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Observational validation of the candidatesWe target the candidate binaries by campaigns of photometry and stellar occultation observations from different sites. The goal is to attempt to validate the presence of the companions by other techniques, independent from the astrometric detection. |
Final study of the physical propertiesEventually, all the properties derived by astrometry, photometry, occultations, and data available from other sources, are assembled in a coherent picture, providing the most complete possible data set of physical properties for the new binaries. |
Citizen science
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GaiaMoons exploits networks of observers of stellar occultations, very useful to validate the discoveris of binary asteroids. GaiaMoons actively supports the collaboration with a large comunity of amateur astronomer by exploiting the ACROSS platform. |
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ANAtOLIA TOMI ACROSS C2PU EUCLID HAYABUSA-2 HERA ANDES LOFAR METEOSPACE NANOSATELLITES OSIRIS-REX PLATO SPEED CHARA/SPICA SKA VEGA WEAVE
Il y a actuellement 20 projets :Missions spatiales - Instruments pour les grands télescopes - Bancs de tests, prototypes - Projets éducatifs - Projets logiciels
Missions spatiales
Instruments pour les grands télescopes
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WEAVE
un spectromètre multi-objets pour le WHT -
VEGA
Instrument visible pour l'interféromètre CHARA -
SKA
le plus grand radiotélescope de tous les temps -
LOFAR
la radioastronomie à basses fréquences
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ANDES
Un spectromètre très haute résolution pour l'ELT
site du consortium
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MOSAIC
Un spectromètre multi-objets pour l'ELT
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SPICA
Un instrument visible nouvelle génération pour CHARA et le VLTI -
METEOSPACE
Un télescope H-alpha pour la surveillance de l’activité solaire
Bancs de tests, prototypes
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SPEED
Banc de tests pour les pupilles segmentées des ELT
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FRIEND
Banc de tests d'optique fibrée pour l'interférométrie dans le visible -
CIAO
band de test sur le ciel d'optique adaptative
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HFT
Démonstrateur de nouvelles techniques de suivi de franges
Projets éducatifs
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C2PU
Télescope pédagogique du plateau de Calern -
NANOSATELLITES
Faire construire des satellites par des étudiants -
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Projets logiciels
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EFISOFT
Fédérer les efforts logiciels pour l'E-ELT -
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Agenda
UMR LAGRANGE
Observatoire de la Côte d’Azur
Boulevard de l’Observatoire
CS 34229 - F 06304 NICE Cedex 4
Tél. : +33 (0)4 92 00 30 11
Fax : +33 (0)4 92 00 30 33
