... The spectrum of the brightest star, our Sun, shows several dark gaps perpendicular to the flow of it’s colours (figure 1). These so called spectral absorption lines where discovered in 1802 by the English scientist William Wollaston. ... Some stars as Pollux show a spectrum similar to that of our sun with strong Ca II and Fe II lines, others as Sirius or Vega show strong absorption lines of hydrogen, others, as Mira show very complicated spectra due to molecular absorption lines (see figure 5). ...

... 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 Second U.S. Naval Observatory CCD Astrograph Catalog ( UCAC2 ) Table of Contents 1) Introduction 2) Summary of the Project a) Observations and Instrumentation b) Reductions of UCAC Observations c) Computation of Proper Motions 3) Properties of the Catalog and Important Notes For the User a) Sky Coverage b) Completeness c) Positions, Proper Motions and Error Calculations d) UCAC2 Magnitudes e) 2MASS Photometry f) Non-stellar ... All stars in the UCAC2 have proper motions. ...