... Abstract: The database we announce contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants of the materials of astronomical interest: different silicates, ices, oxides, sulfides, carbides, carbonaceous species from amorphous carbon to graphite and diamonds, etc. ... The main topics of the database are the optical constants of materials involved in astronomical calculations. ...

... We also analyze Chandra X-ray archive data for the Mon R2 region and find IRS 3 A and IRS 3 C to be sources of hard (3 - 10 keV) and variable X-ray emission , suggesting plasma temperatures of at least 50 в 106 K. The similarity of the X-ray properties to those of Class I protostars suggests magnetic interaction between the protostars and their circumstellar disks to be the origin of the X-ray ... 2002). ... Upper Upper Lower Lower K-band Images of Mon R2 IRS 3. ... X-ray results. ...