... Telescopes . ... But regardless of where you observe from or whether or not you have a telescope, exploring the many aspects of astronomy can be an exciting hobby. It can be an activity shared with thousands of other amateurs all over the world. ... Or it might be pursued more actively by joining a local astronomy club like the Amateur Telescope Makers of Boston and learning by direct association with other amateurs. ... Copyright (c) Amateur Telescope Makers of Boston, Inc. ...

... Chilingarian, I., Melchior, A.-L., Zolotukhin, I. 2010: Analytical approximations of K -corrections in optical and near-infrared bands , accepted to MNRAS (arXiv:1002.2360) . ... K-Corrections in the optical and near-infrared , Analytical approximations of K-corrections in optical and near-infrared bands , photometric properties of galaxies , K-corrections approximation redshift and one observed colour , transform observed spectral energy distributions (SED) , software to estimate K-corrections , ...

... Ciel Espace, le magazine qui vous guide toujours plus loin . ... des pages consacr†йes †а la publication de vos photos Mais c'est aussi une vraie communaut†й avec laquelle partager votre passion et nourrir votre curiosit†й. Accueil Mati†иre noire : une observation d†йfie les astronomes . ... A la une . ... En effet, selon les mod†иles th†йoriques, les concentrations de mati†иre noire sont les lieux o†µ naissent les galaxies. ... Une mati†иre noire au comportement ordinaire ? ... Etat du ciel . ...

SITE 2010 Comprehensive Characterization of Astronomical Sites Kislovodsk, Russia, 49 October 2010 Conference Summary Marc S. Sarazin*a a European Southern Observatory, Garching, Germany Abstract The main topics discussed during the Site 2010 conference are outlined and the outcome is described. Keywords: Astronomical Site testing, precipitable water vapor, atmospheric turbulence, cloudiness, seeing 1. ... Site surveys for National observatory projects in China, India, and Iran benefit from this. ...

... GRIN lenses for telecommunication optics applications ? GTC (gradient telecom) lenses. ... GTC lenses are used in different fiber-optic devices: collimators, couplers, isolators and WDM etc . ... 2.Diameter . GTC lenses diameters are 1.0 mm, 1.8 mm, 3.0 mm and 4.0mm. ... 1.0 mm -3.0 mm diam GTC lenses are supplied in 0.22P, 0.23P, 0.25P, 0.27P and 0.29P length. 4.0 mm diam GTC lenses are supplied in 0.11P length. ... GTC . ... 3 scratches with 5mkm max width and 200mkm max length are allowed . ...