Dust Envelope around the Carbon Star RW LMi

Results of infrared photometric observations of RW LMi in the $JHKLM$ bands are presented. The observations were carried out from 1994 to 2024. Based on observations of 17\,pulsation cycles of the star, new brightness ephemerides were established: ${\rm JD}_{\rm max}=2459677\,.\!\!^{\rm d}0 + 610\,.\!\!^{\rm d}9E$. A sinusoidal trend of the average brightness level was found. Its period is about 7300\;days and its amplitude is approximately $1^{\rm m}$ in the $JHK$ bands. From the energy distribution in the spectrum in the wavelength range of 0.5--100\;$\mu$m, an estimate of the bolometric flux at the maximum brightness was obtained: $F_{\rm bol}=2.6\times 10^{-6}$\;erg\,s$^{-1}$\,cm$^{-2}$. This corresponds to the luminosity $L_{\rm max}\approx8500\,L_\odot$. Modeling of the RW\,LMi circumstellar envelope radiation was performed with the \texttt{RAMDC-3D} program. The simulation was carried out in the approximation of a spherically symmetric envelope shape with a constant mass-loss rate. The main envelope parameters are: the optical depth $\tau_V\approx12.7$, the inner radius $R_{\rm in}\approx8$\;AU, the outer radius $R_{\rm out}\approx17\,000$\;AU, and the mass-loss rate $\dot M=6\times10^{-6}\;M_\odot$\,yr$^{-1}$.