Techniques d'observation spectroscopique d'astéroïdes

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Conclusions and perspectives
tel-00785991, version 1 - 7 Feb 2013
During my Ph. D. studies, I applied the spectral techniques to determination of asteroids physical
properties. The work consists of three main activities: telescope observations, developing of
the methods and tools for asteroid spectral analysis, and interpretation of the asteroids spectra.
I observed for more than 40 hours on NASA SpeX/IRTF, in remote control from CODAM
Center(Paris). The purpose of these observations was to obtain NIR asteroid spectra. The
results where partially published [Birlan et al., 2011, Popescu et al., 2011, Birlan & Popescu,
2011, Birlan et al., 2012, Popescu et al., 2012b].
Additional to the main subject of the thesis, I observed around 20 nights for asteroids discovery
(with particular interest for NEAs), recovery and follow up. These observations were
made from Obsv. de Haute Provence (France), Pic du Midi (France), and ORM in La Palma
(Canary). The results of these campaigns appeared in 12 Minor Planet Circulars and 21 Minor
Planet Electronic Circulars.
For analysis of asteroids NIR spectra I applied the well known methods (taxonomic classifications,
band analyses and comparative mineralogy) and I proposed new mathematical approaches
for spectral comparison and taxonomical classification. I implemented all these methods
into routines of a software package called M4AST (Modeling for Asteroids). The second
component of M4AST is the spectral database which has around 2,700 asteroid spectra obtained
from our observing program and different collaborations. The spectra from the database
are in a standard format and are fully available for download. I developed M4AST using Octave
computation environment, PHP programming language, and GNUPlot tools (with the free
GNU license).
M4AST was conceived to be fully available via a web interface and can be used by the scientific
community. Together with my colleagues, I presented in a paper [Popescu et al., 2012b]
the interfaces available to access this software tool and the algorithms behind each method used
to perform the spectral analysis. The robustness of the routines has been demonstrated by using
the software to model a variety of spectra.
Together with my colleagues, I obtained and analyzed NIR spectra for eight near-Earth
asteroids [Popescu et al., 2011]. Four of the observed objects have delta - V lower than 7