| Name: Monoswini Chakravorty |
| Affiliation: Assam University Silchar |
| Conference ID: ASI2026_672 |
| Title: A Comparative Polarimetric Study of 24P/Schaumasse (Short-Period) and C/2016 R2 (Long-Period) Comets |
| Abstract Type: Poster |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Monoswini Chakravorty(Assam University Silchar, Assam-488011, India), Himadri Sekhar Das(Assam University Silchar, Assam-488011, India) |
| Abstract: Polarimetry provides a powerful diagnostic of cometary dust properties, including grain size, morphology, and composition. We present a comparative polarimetric study of two comets from distinct dynamical classes: the short-period comet 24P/Schaumasse and the long-period comet C/2016 R2 (PANSTARRS), observed at phase angles of 41.0° and 7.74°, respectively. Spatial variations in dust properties across the coma were investigated using aperture polarimetry and polarization maps, while the coma structure was analyzed through radial intensity profiles.
The short-period comet 24P/Schaumasse exhibits relatively shallow radial intensity slopes (−0.202 and −0.172), consistent with sustained dust emission dominated by slowly dispersing particles. In contrast, C/2016 R2 (PANSTARRS) shows significantly steeper sunward and tailward slopes (−0.555 and −0.395), indicating a rapid decline in brightness and non-steady dust dynamics.
Polarimetric measurements reveal marked differences between the two comets that align with their distinct viewing geometries and compositions. At a phase angle of 41°, 24P/Schaumasse exhibits positive polarization (P ≈ 5.22%), typical of dust-dominated scattering at intermediate phase angles. Conversely, C/2016 R2 (PANSTARRS), observed at a small phase angle of 7.74°, exhibits low negative polarization (P ≈ −0.88%). While negative polarization is expected at such low phase angles due to backscattering, this measurement is consistent with the gas-rich and dust-poor environment of C/2016 R2. These results demonstrate the effectiveness of polarimetry in distinguishing dust properties and evolutionary behavior in comets from different dynamical populations.
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