Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact
We have monitored the Didymos–Dimorphos binary asteroid in spectropolarimetric mode in the optical range before and after the DART impact. The ultimate goal was to obtain constraints on the characteristics of the ejected dust for modeling purposes. Before impact, Didymos exhibited a linear polarizat...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal Letters |
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| Online Access: | https://doi.org/10.3847/2041-8213/acb261 |
| _version_ | 1797697196831801344 |
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| author | Stefano Bagnulo Zuri Gray Mikael Granvik Alberto Cellino Ludmilla Kolokolova Karri Muinonen Olga Muñoz Cyrielle Opitom Antti Penttilä Colin Snodgrass |
| author_facet | Stefano Bagnulo Zuri Gray Mikael Granvik Alberto Cellino Ludmilla Kolokolova Karri Muinonen Olga Muñoz Cyrielle Opitom Antti Penttilä Colin Snodgrass |
| author_sort | Stefano Bagnulo |
| collection | DOAJ |
| description | We have monitored the Didymos–Dimorphos binary asteroid in spectropolarimetric mode in the optical range before and after the DART impact. The ultimate goal was to obtain constraints on the characteristics of the ejected dust for modeling purposes. Before impact, Didymos exhibited a linear polarization rapidly increasing with phase angle, reaching a level of ∼5% in the blue and ∼4.5% in the red. The shape of the polarization spectrum was anticorrelated with that of its reflectance spectrum, which appeared typical of an S-class asteroid. After impact, the level of polarization dropped by about 1 percentage point (pp) in the blue band and about 0.5 pp in the red band, then continued to linearly increase with phase angle, with a slope similar to that measured prior to impact. The polarization spectra, once normalized by their values at an arbitrary wavelength, show very little or no change over the course of all observations before and after impact. The lack of any remarkable change in the shape of the polarization spectrum after impact suggests that the way in which polarization varies with wavelength depends on the composition of the scattering material, rather than on its structure, be this a surface or a debris cloud. |
| first_indexed | 2024-03-12T03:36:49Z |
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| id | doaj.art-7ea8941da0d1499aad493eb16a1f515e |
| institution | Directory Open Access Journal |
| issn | 2041-8205 |
| language | English |
| last_indexed | 2024-03-12T03:36:49Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal Letters |
| spelling | doaj.art-7ea8941da0d1499aad493eb16a1f515e2023-09-03T13:08:53ZengIOP PublishingThe Astrophysical Journal Letters2041-82052023-01-019452L3810.3847/2041-8213/acb261Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART ImpactStefano Bagnulo0https://orcid.org/0000-0002-7156-8029Zuri Gray1https://orcid.org/0000-0002-6610-1897Mikael Granvik2https://orcid.org/0000-0002-5624-1888Alberto Cellino3https://orcid.org/0000-0002-6645-334XLudmilla Kolokolova4https://orcid.org/0000-0002-9321-3202Karri Muinonen5https://orcid.org/0000-0001-8058-2642Olga Muñoz6https://orcid.org/0000-0002-5138-3932Cyrielle Opitom7https://orcid.org/0000-0002-9298-7484Antti Penttilä8https://orcid.org/0000-0001-7403-1721Colin Snodgrass9https://orcid.org/0000-0001-9328-2905Armagh Observatory & Planetarium , College Hill, Armagh, BT61 9DG, UK ; stefano.bagnulo@armagh.ac.ukArmagh Observatory & Planetarium , College Hill, Armagh, BT61 9DG, UK ; stefano.bagnulo@armagh.ac.uk; Mullard Space Science Laboratory, University College London , Holmbury St. Mary, Dorking RH5 6NT, UKDepartment of Physics, PO Box 64, FI-00014 University of Helsinki , Finland; Asteroid Engineering Laboratory, Luleå University of Technology , Box 848, SE-98128 Kiruna, SwedenINAF—Osservatorio Astrofisico di Torino , I-10025 Pino Torinese, ItalyDepartment of Astronomy, University of Maryland , College Park, MD 20742-2421, USADepartment of Physics, PO Box 64, FI-00014 University of Helsinki , FinlandInstituto de Astrofísica de Andalucía , CSIC, Glorieta de la Astronomia s/n, E-18008 Granada, SpainInstitute for Astronomy, University of Edinburgh , Royal Observatory, Edinburgh, EH9 3HJ, UKDepartment of Physics, PO Box 64, FI-00014 University of Helsinki , FinlandInstitute for Astronomy, University of Edinburgh , Royal Observatory, Edinburgh, EH9 3HJ, UKWe have monitored the Didymos–Dimorphos binary asteroid in spectropolarimetric mode in the optical range before and after the DART impact. The ultimate goal was to obtain constraints on the characteristics of the ejected dust for modeling purposes. Before impact, Didymos exhibited a linear polarization rapidly increasing with phase angle, reaching a level of ∼5% in the blue and ∼4.5% in the red. The shape of the polarization spectrum was anticorrelated with that of its reflectance spectrum, which appeared typical of an S-class asteroid. After impact, the level of polarization dropped by about 1 percentage point (pp) in the blue band and about 0.5 pp in the red band, then continued to linearly increase with phase angle, with a slope similar to that measured prior to impact. The polarization spectra, once normalized by their values at an arbitrary wavelength, show very little or no change over the course of all observations before and after impact. The lack of any remarkable change in the shape of the polarization spectrum after impact suggests that the way in which polarization varies with wavelength depends on the composition of the scattering material, rather than on its structure, be this a surface or a debris cloud.https://doi.org/10.3847/2041-8213/acb261Near-Earth objectsSpectropolarimetry |
| spellingShingle | Stefano Bagnulo Zuri Gray Mikael Granvik Alberto Cellino Ludmilla Kolokolova Karri Muinonen Olga Muñoz Cyrielle Opitom Antti Penttilä Colin Snodgrass Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact The Astrophysical Journal Letters Near-Earth objects Spectropolarimetry |
| title | Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact |
| title_full | Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact |
| title_fullStr | Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact |
| title_full_unstemmed | Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact |
| title_short | Optical Spectropolarimetry of Binary Asteroid Didymos–Dimorphos before and after the DART Impact |
| title_sort | optical spectropolarimetry of binary asteroid didymos dimorphos before and after the dart impact |
| topic | Near-Earth objects Spectropolarimetry |
| url | https://doi.org/10.3847/2041-8213/acb261 |
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