Phase-Polarization Analysis of Asteroids 13 Egeria and 511 Davida: New Low Phase Angle Observations and C-Type Comparisons

We present a comprehensive polarimetric analysis of the main-belt asteroids 13 Egeria and 511 Davida, based on new R-band observations combined with previously published data in the R, V, and G bands. The new observations have been conducted using the 1.04 m Sampurnanand Optical Telescope at phase angles of $$\alpha = 5.52^\circ $$ for Egeria and $$\alpha = 2.21$$ ° for Davida, covering a previously unexplored region of the phase–polarization curve for both objects. At these low phase angles, we have detected significant negative polarization: $${{P}_{{\text{r}}}} = - 1.72 \pm 0.06$$ for Egeria and $${{P}_{{\text{r}}}} = - 0.91 \pm 0.10$$ for Davida. These measurements provide valuable constraints within the negative polarization branch and significantly improve the overall phase–polarization profiles of the two asteroids. The inclusion of these new data enables more accurate determinations of key polarimetric parameters, including minimum polarization $$({{P}_{{{\text{min}}}}})$$ , inversion angle $${{\alpha }_{{{\text{inv}}}}}$$ , and polarimetric slope $$\left( h \right)$$ . To maintain internal consistency, our analysis focuses on R-band observations supplemented by multi-band archival data. A comparative study with other well-characterized C-type asteroids reveals both shared features and subtle differences, potentially indicative of variations in surface texture or composition. These findings enhance our understanding of the surface scattering properties of Egeria and Davida and contribute to the broader characterization of C-type asteroid diversity, highlighting the importance of polarimetric studies for understanding surface properties and regolith characteristics within taxonomic groups, offering new insights into the nature of primitive bodies in the solar system.