Optical Properties of Interstellar Dust around the Orion A Molecular Cloud

We have studied optical properties of interstellar dust around the Orion A molecular cloud to investigate size distribution and composition grains. is one most clouds in solar vicinity ($d \simeq 400\ \rm{pc}$). In this paper, we used near-infrared photometric data. The data were obtained by $BVRI$ bands imaging observations. consisting $JHK_{S}$ taken from 2MASS point source catalog. produced some color excess maps A, measured their ratios such as $E(R-I)/E(B-V)$. order properties, compared observed with results simulation performed Naoi T. et al. (2021) who calculated extinction wavelengths based on a standard model; they assumed power-law grain-size an upper cutoff radius $graphite$ $silicate$ dominant components. As result, found that $\simeq 0.3$ $\rm{\mu}$m, predominates (with fraction grater than $93$ %). addition, further derived total-to-selective ratio $R_{V}$ $A_{V}$ $E(B-V)$, it model calculations. Dust (i.e., $graphite/silicate$) almost consistent those ratios.