Intermediate size asteroids: Photoelectric photometry of 8 objects

Http Www Theses Fr, 1997

2000

Le choix d'une technique et sa validation constitue une préoccupation majeure pour le biologiste dont le souci permanent est de garantir la fiabilité des résultats. Ce travail expérimental, est une évaluation des performances analytiques d'un réactif Biuret destiné au dosage manuel des protides totaux dans notre laboratoire. Nous avons utilisé une gamme de solutions croissantes d'albumine et des contrôles du commerce. Le Biuret éprouvé est proche de celui proposé par Gornall. Le protocole suivi est inspiré du protocole de Validation des Techniques Valtec. La limite haute de linéarité est à 100g/L et l'étalonnage montre une courbe linéaire. La limite de détection est à 1,28g/L et le seuil de quantification à 4,25g/L. Les coefficients de variation (CV) ou de reproductibilité sont inférieurs à ceux de la Société Française de Biologie Clinique (SFBC), de même pour la justesse et l'inexactitude dont les valeurs sont inférieures aux limites de la SFBC. Le réactif éprouvé présente d'excellentes performances analytiques en termes de détectabilité, de stabilité, de reproductibilité, de justesse et d'inexactitude sauf pour la limite de linéarité. Cette méthode est introduite dans notre laboratoire comme technique manuelle de dosage des protidémies aux concentrations basses et moyennes.

Solar Physics, 1974

A series of plates of the solar corona were obtained during the total solar eclipse of July 10th, 1972 near Anadyr (U.S.S.R.) using a standard eclipse coronagraph of Ø = 20 cm and F = 300 cm. A neutral radial filter (Figure 2) was specially conceived to enable the study of the corona up to 5 R ⊙ and also that of the lunar background. The absolute calibration takes into consideration the different components of the recorded radiation: the K and F corona, the sky background B c, the coronal aureola B aur and details of the earthshine on the lunar background. The brightness of the corona (K + F) is given along the N-S and E-W axes and also the total brightness recorded along the tangential directions, at selected radial distances. The photometry shows that the K corona in 1972 was very heterogeneous and its mean brightness close to that of a corona of maximum activity for r < 2 R ⊙. Moreover, the difference of brightness between the equator and the poles for r > 2 R bd is about twice larger than in the Van de Hulst' model of the corona of minimum activity. At the north pole, a coronal ‘hole’ clearly appears.

2003

A Near-Earth object (NEO) astrometric follow-up program was started at Barão Geraldo (Campinas, SP, Brazil) in 1996 and transferred to Observatório Abrahão de Moraes (Valinhos, SP) in early 1998. Since mid-1999, this program uses a 36-cm telescope on a robotic mount, which is remotely operated from Barão Geraldo through an internet connection. The planning of observation sessions is made with the help of especially developed software which automatically allocates telescope time to the targets which one wishes to observe on a given night, taking into account several observational constraints and the physical characteristics of the telescope and robotic mount. The output of the time allocation program is a set of scripts containing commands for the telescope and CCD camera, and topocentric ephemeris for the various solar-system targets (whose computation includes full planetary perturbations). These scripts are uploaded to the telescope control computer, and executed autonomously by t...

Astronomy &amp; Astrophysics, 2016

Context. Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. These efforts already provided deep insight into physical properties of main-belt asteroids or large collisional families. Going into finer detail (e.g., smaller collisional families, asteroids with sizes 20 km) requires knowledge of physical parameters of more objects. Aims. We aim to increase the number of asteroid shape models and rotation states. Such results provide important input for further studies, such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides bulk density estimates in combination with known masses, but also constrains theoretical collisional and evolutional models of the solar system. Methods. We use all available disk-integrated optical data (i.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as input for the convex inversion method, and derive 3D shape models of asteroids together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that 100 observers who submit their optical data to publicly available databases. Results. We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature, or for which masses will most likely be determined from their gravitational influence on smaller bodies whose orbital deflections will be observed by the ESA Gaia astrometric mission. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and three near-Earth asteroids. The shape model revisions and determinations were enabled by using additional optical data from recent apparitions for shape optimization.

2001

La photoproduction de mésons eta sur l&#39;hydrogène a été mesurée du seuil jusqu&#39;à une énergie de 1100 MeV dans l&#39;expérience GRAAL effectuée en 1996-97 à l&#39;ESRF à Grenoble dans une collaboration entre des groupes Italiens Français et Russes. Un faisceau de photons étiquetés et polarisés linéairement a été produit en rétrodiffusant un faisceau laser sur le faisceau d&#39;électrons de 6 GeV de l&#39;anneau de l&#39;ESRF. La cible a été d&#39;hydrogène liquide de 3 cm. Un détecteur 4 pi a été utilisé, composé de trois couches de détecteurs: chambres à fil, compteurs à scintillation et calorimètres. Nous avions la charge d&#39;installer et d&#39;étalonner un double mur de scintillants (3x3 m) conçu pour détecter aux angles avant (1-25°) les particules chargées et mesurer leur pertes d&#39;énergie et leurs temps de vol. Nous avons analysé les résultats de la réaction g p -&gt; eta p en identifant le eta dans le calorimètre latéral qui est une boule BGO et en détectant le pro...

Exo- …, 2002

Proceedings ofthe SecondEuropean Workshop on Exo/Astrobiology, Graz, Austria, 16-19 September 2002 (ESA SP-518, November 2002) © European Space Agency • Provided by the NASA Astrophysics Data System BIODEVICES FOR THE DETECTION OF SPACE RADIATION EFFECT ON ...

Astronomy & Astrophysics Supplement Series, 1982

Photoelectric and spectrographic observations of the suspected variable rho Vir are reported. Analysis of all the available photometric data has been made. The results do not show a clear regular variability of this star.

The Astronomical Journal, 1990