Comet 7P/Pons-Winnecke was observed from the Calar Alto Observatory (Spain) for four months during the 2021 inbound apparition. Broad-band visible images were taken between 1.71 and 1.25 AU pre-perihelion, while long-slit spectrophotometric data were taken at ∼ 1.25 AU pre-perihelion. This dataset has been complemented with three r-Sloan images observed from Zwicky Transient Facility (ZTF) to model the physical properties and loss rate of the dust with a forward Monte Carlo dust tail code. The model fits the observed isophotes well for most observations. The peak dust production rate was measured at 83 kg s−1, 15 days after perihelion. The particle terminal speed ranges from 3 m s−1 for 0.1 m particles to 23 m s−1 for 5 μm particles. Regarding the gas production from spectra, CN and C2 show asymmetric emission between the sunward and antisunward directions beyond the data uncertainties and error propagation, while a clear asymmetry for C3 cannot be definitively claimed. Average production rates for CN, C2, and C3 near 2021 perihelion are 1.15 ×1024, 2.32×1024, and 1.69×1023 s−1, respectively. The dust-to-gas mass ratio value is estimated to be around 2, suggesting a dust-rich composition. Based on the gas composition and the Afρ value, we classify 7P/Pons-Winnecke as having a typical composition for Jupiter Family comets, with some C3 depletion. Given the limited previous knowledge, our work contributes to expanding the understanding of the activity and characteristics of 7P/Pons-Winnecke.
@article{arxiv.2503.02434,
title = {Activity of comet 7P/Pons-Winnecke during the 2021 apparition},
author = {Irene Mariblanca-Escalona and Luisa M. Lara and Fernando Moreno and Pedro J. Gutiérrez and Marçal Evangelista-Santana},
journal= {arXiv preprint arXiv:2503.02434},
year = {2025}
}