Techniques d'observation spectroscopique d'astéroïdes

40 CHAPTER 1. WHY ASTEROIDS?
Mega-Archive - the database which includes the individual instrument archives, namely the
observing logs for their science CCD images or plates available from a collection of instruments
and telescope around the globe. The Mega-Archive is an open project allowing
other instrument archives to be added later for exploration by anybody who would like to
contribute. As of March 2012, the Mega-Archive counts about two million images from
20 instrument archives available for search via Mega-Precovery. This include all ESO
imaging instruments, the INT WFC, CFHTLS, Subaru Suprime-Cam, Blanco Mosaic-2
and AAT WFI archives;
tel-00785991, version 1 - 7 Feb 2013
Mega-Precovery software 4 for data mining the Mega-Archive for the images containing
one or a more desired catalogued object (NEAs, PHAs or other asteroids) included in a
local daily updated MPC database. The Mega-Precovery software is written in PHP, being
embedded on the EURONEAR website as a public access application under the Observing
Tools section. The flowchart of the project is given in Fig. 1.3.
The output of Mega-Precovery consists in a list including the images and the corresponding
CCD number predicted to contain the queried object(s). The results are displayed both in
the web interface (visible only at the end of the run) and sent via e-mail to the user (in case
this option was selected). The user can search the images in the online instrumental archive,
then download, inspect and measure the data related to this asteroid according to his/her own
scientific interest (astrometry, photometry, etc).
Inside EURONEAR team [Vaduvescu et al., 2012], I searched for randomly appearances
of known Near Earth Asteroids (NEAs) and Potentially Hazardous Asteroids (PHAs) in ES-
O/MPG WFI(Wide Field Imager) and INT WFC archives (these are two wide field 2m class
telescope ). A total of 152 asteroids (108 NEAs and 44 PHAs) were identified and measured
on 761 images and their astrometry was reported to Minor Planet Center (MPC). Both recoveries
and precoveries (apparitions of the object in the images before official discovery) were
reported, including prolonged orbital arcs for 18 precovered asteroids and 10 recoveries, plus
other 124 recoveries.
All the astrometric measurements were submitted to Minor Planet Center http://www.
minorplanetcenter.org/iau/mpc.html. These measurements appear in 12 Minor
Planet Circulars and 21 Minor Planet Electronic Circulars: (79530, 1 (2012); 78894, 9 (2012);
78437, 11 (2012); 77699, 2 (2012); 77266, 11 (2011); 77265, 3 (2011); 77173, 6 (2011); 75198,
5 (2011); 74036, 3 (2011); 72456, 4 (2010); 70198, 9 (2010); 69303, 1 (2010)); (2012-E19
(2012); 2012-D102 (2012); 2012-D82 (2012); 2011-W52 (2011); 2011-W45 (2011); 2011-
W44 (2011); 2011-W33 (2011); 2011-W29 (2011); 2011-W28 (2011); 2011-W27 (2011);
2011-W25 (2011); 2011-W22 (2011); 2011-W12 (2011); 2011-E19 (2011); 2011-E14 (2011);
2011-E13 (2011); 2011-E12 (2011); 2011-E11 (2011); 2010-W13 (2010); 2010-W12 (2010);
2010-W11 (2010)). An example of such circular is given in Fig. 1.4.
4 http://euronear.imcce.fr/tiki-index.php?page=MegaPrecovery