[en] On 2020 April 29, the near-Earth object (52768) 1998 OR2 experienced a close approach to Earth at a distance of 16.4 lunar distances (LD). 1998 OR2 is a potentially hazardous asteroid of absolute magnitude H = 16.04 that can currently come as close to Earth as 3.4 LD. We report here observations of this object in polarimetry, photometry, and radar. Our observations show that the physical characteristics of 1998 OR2 are similar to those of both M- and S-type asteroids. Arecibo's radar observations provide a high radar albedo of sigma _OC = 0.29 ± 0.08, suggesting that metals are present in 1998 OR2 near-surface. We find a circular polarization ratio of μc = 0.291 ± 0.012, and the delay-Doppler images show that the surface of 1998 OR2 is a top-shape asteroid with large-scale structures such as large craters and concavities. The polarimetric observations display a consistent variation of the polarimetric response as a function of the rotational phase, suggesting that the surface of 1998 OR2 is heterogeneous. Color observations suggest an X-complex taxonomy in the Bus–DeMeo classification. Combining optical polarization, radar, and two epochs from the NEOWISE satellite observations, we derived an equivalent diameter of D = 1.80 ± 0.1 km and a visual albedo pv = 0.21 ± 0.02. Photometric and radar data provide a sidereal rotation period of P = 4.10872 ± 0.00001 hr, a pole orientation of (332.°3 ± 5°, 20.°7 ± 5°), and a shape model with dimensions of ({2.08}_{-0.10}^{+0.10}, {1.93}_{-0.10}^{+0.10},{1.60}_{-0.05}^{+0.05}) km.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Devogele, Maxime ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > COMets METeors and Asteroids (COMETA) ; Arecibo Observatory
McGilvray, Anna; Arecibo Observatory
MacLennan, Eric; University of Helsinki, Department of Physics
Monchinski, Courteney; Tokyo Institute of Technology, Ookayama, Japan
Marshall, Sean E.; Arecibo Observatory
Hickson, Dylan; Colorado School of Mines
Virkki, Anne; University of Helsinki, Department of Physics
Giorgini, Jon D.; Jet Propulsion Laboratory
Abe, Lyu; Université Côte d'Azur, CNRS, OCA, LAGRANGE, France
scite shows how a scientific paper has been cited by providing the context of the citation, a classification describing whether it supports, mentions, or contrasts the cited claim, and a label indicating in which section the citation was made.
Bibliography
Aznar-Macías, A. 2020, Asteroid Photometric Survey, Near-Earth Asteroids Lightcurves, https://aptog.com/?p=916
Barnouin, O., Daly, M., Palmer, E., et al. 2019, NatGe, 12, 247
Battle, A., Reddy, V., Sanchez, J. A., et al. 2022, PSJ, 3, 226
Belskaya, I., Cellino, A., Gil-Hutton, R., Muinonen, K., & Shkuratov, Y. 2015, Asteroids IV (Tucson, AZ: Univ. Arizona Press), 151
Bendjoya, P., Cellino, A., Rivet, J.-P., et al. 2022, A&A, 665, A66
Benner, L. A. M., Ostro, S. J., Magri, C., et al. 2008, Icar, 198, 294
Betzler, A. S., & Novaes, A. B. 2009, MPBu, 36, 145
Borisov, G., Devogèle, M., Cellino, A., et al. 2018, MNRAS Letters, 480, L131
Bowell, E., Hapke, B., Domingue, D., et al. 1989, Asteroids II (Tucson, AZ: Univ. Arizona Press), 524
Bus, S. J., & Binzel, R. P. 2002, Icar, 158, 146
Castro-Chacón, J., Gil-Hutton, R., Vélez, J. R., & Reyes-Ruiz, M. 2022, P&SS, 213, 105428
Cellino, A., Ammannito, E., Magni, G., et al. 2016, MNRAS, 456, 248
Cellino, A., Bagnulo, S., Gil-Hutton, R., et al. 2015, MNRAS, 451, 3473
Colazo, M., Stechina, A., Fornari, C., et al. 2021, MPBu, 48, 50
Consolmagno, G., Britt, D., & Macke, R. 2008, ChEG, 68, 1
DeMeo, F. E., Binzel, R. P., Slivan, S. M., & Bus, S. J. 2009, Icar, 202, 160
Devogèle, M., Cellino, A., Bagnulo, S., et al. 2017, MNRAS, 465, 4335
Devogèle, M., Cellino, A., Borisov, G., et al. 2018a, MNRAS, 479, 3498
Devogèle, M., Tanga, P., Cellino, A., et al. 2018b, Icar, 304, 31
Emery, J., Fernández, Y., Kelley, M., et al. 2014, Icar, 234, 17
Fornasier, S., Clark, B. E., Dotto, E., et al. 2010, Icar, 210, 655
Franco, L., Marchini, A., Saya, L.-F., et al. 2020, MPBu, 47, 242
Hanus, J., Durech, J., Oszkiewicz, D., et al. 2016, A&A, 586, A108
Hapke, B. 1984, Icar, 59, 41
Harris, A. W. 1998, Icar, 131, 291
Hickson, D. C., Boivin, A., Daly, M. G., et al. 2018, Icar, 306, 16
Hickson, D. C., Virkki, A. K., Perillat, P., Nolan, M. C., & Bhiravarasu, S. S. 2021, PSJ, 2, 30
Hodapp, K., Kaiser, N., Aussel, H., et al. 2004, AN, 325, 636
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.