The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...

... We explore the structures immediately surrounding the intermediate-mass young stellar object R Mon with bispec- trum speckle interferometry, conventional near-infrared imaging and by analyzing optical HST archive data. Our near-infrared speckle images with unprecedented diffraction-limited resolution of 55 mas (44 AU; H -band) and 76 mas (61 AU; K -band) represent the highest resolution R Mon images obtained so far and exhibit previously unseen complex structures. ... The features 1­5 are marked. ...