Here we compare the optical properties of porous nonspherical particles of two kinds: . ... For each considered value of porosity P, we give first 8 figures on 1 page that show the dependence of the dimesionless extinction (Q ext ) and linear polarization (Q pol ) cross-sections particles on their difraction parameter x v = 2 pi r v / lambda, where r v is the radius of a sphere which volume is equal to that of a nonspherical particle, lambda is the wavelength of incident radiation. ...

... 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. ...