... These Facts and Questions pages mainly tell you how to use the Aberrator-interface and also explain the nature of the aberrations. ... Airy disc: the brightest spot of light when you look at a star in focus. This disc can contain a maximum of 84% of all the light that arrives from a star (perfect refractor telescope). MCT : Maksutov-Cassegrain telescope. A closed-tube mirror-telescope with a secondary obstruction. Less common than the SCT, this telescope uses a corrector (real glass). ...

... The author attempts to approach the problem from the positions of systems analysis with account for the ideological grounds and history of space activities in Russia and abroad, comparing its current interpretation with the initial goals posed by leading theoreticians and practitioners who stood at the cradle of the space exploration era. ... The space systems recognized in Russia as priority projects are largely developed with violations of the systems approach principles. ...

... 000, 1­12 (2009) Printed 11 February 2010 A (MN L TEX style file v2.2) Analytical approximations of K -corrections in optical and near-infrared bands I1gor V. Chilingarian1 2 ,2,3 , Anne-Laure Melchior 1,4 and Ivan Yu. ... Received 2010 February 01; in original form 2009 August 14 ABSTRACT To compare photometric properties of galaxies at different redshifts, the fluxes need to be corrected for the changes of effective rest-frame wavelengths of filter bandpasses, called K -corrections. ... Table 1. ...

The Database of Close Binary Systems . ... Team . ... This web-based interactive database is being developed and maintained by a team at the Sternberg Astronomical Institute of the Moscow State University . The project is an on-line extension of our catalogue on "Highly Evolved Close Binary Stars" (volumes I, II) published by Gordon and Breach in 1996. As of September 2009, the database (both the software and the content) is in its development/testing phase. ...