Characterization of Temporarily Captured Minimoon 2020 CD 3 by Keck Time-resolved Spectrophotometry
| Autor: | Hanjie Tan, Kaushik De, M. Hankins, Richard Walters, Rick Burruss, P. Mróz, Shrinivas R. Kulkarni, Russ R. Laher, Kunal Deshmukh, Jeffry Zolkower, Matthew J. Graham, Dmitry A. Duev, Reed Riddle, Josiah N. Purdum, Alessandro Morbidelli, Maayane T. Soumagnac, Lin Yan, Chow-Choong Ngeow, Michael W. Coughlin, Carey M. Lisse, Robert M. Quimby, Timothy R. Holt, Richard Dekany, Ashish Mahabal, Hector Rodriguez, James D. Neill, Zhong-Yi Lin, Shreya Anand, David Hale, Tomas Ahumada, Dennis Bodewits, Chan-Kao Chang, Alexandre Delacroix, Bryce Bolin, Frank J. Masci, Varun Bhalerao, Roger Smith, Chris M. Copperwheat, Mansi M. Kasliwal, Thomas Kupfer, Chen Yen Hsu, Wing-Huen Ip, Kevin B. Burdge, Chengxing Zhai, Christoffer Fremling |
|---|---|
| Přispěvatelé: | Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
Near-Earth object 010504 meteorology & atmospheric sciences Meteoroid medicine.diagnostic_test [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] Imaging spectrometer Astronomy and Astrophysics Astrophysics Albedo 01 natural sciences Photometry (astronomy) Wavelength 13. Climate action Space and Planetary Science Asteroid Spectrophotometry 0103 physical sciences medicine 010303 astronomy & astrophysics ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences |
| Zdroj: | The Astrophysical journal letters The Astrophysical journal letters, Bristol : IOP Publishing, 2020, 900 (2), pp.L45. ⟨10.3847/2041-8213/abae69⟩ |
| ISSN: | 2041-8205 2041-8213 |
| DOI: | 10.3847/2041-8213/abae69⟩ |
| Popis: | We present time-resolved visible spectrophotometry of 2020 CD₃, the second known minimoon. The spectrophotometry was taken with the Keck I/Low Resolution Imaging Spectrometer between wavelengths 434 and 912 nm in the B, g, V, R, I, and RG850 filters as it was leaving the Earth–Moon system on 2020 March 23 UTC. The spectrum of 2020 CD₃ resembles V-type asteroids and some lunar rock samples with a 434–761 nm reddish slope of ~18%/100 nm (g–r = 0.62 ± 0.08 and r–i = 0.21 ± 0.06) with an absorption band at ~900 nm corresponding to i–z = −0.54 ± 0.10. Combining our measured H of 31.9 ± 0.1 with an albedo of 0.35 typical for V-type asteroids, we determine 2020 CD₃'s diameter to be ~0.9 ± 0.1 m, making it the first minimoon and one of the smallest asteroids to be spectrally studied. We use our time-series photometry to detect significant periodic light-curve variations with a period of ~573 s and amplitude of ~1. In addition, we extend the observational arc of 2020 CD₃ to 37 days, to 2020 March 23 UTC. From the improved orbital solution for 2020 CD₃, we estimate the likely duration of its capture to be ~2 yr and the nongravitational perturbation on its orbit due to radiation pressure with an area-to-mass ratio of (6.9 ± 2.4) × 10⁻⁴ m² kg⁻¹ implying a density of 2.3 ± 0.8 g cm⁻³, broadly compatible with other meter-scale asteroids and lunar rock. We searched for prediscovery detections of 2020 CD₃ in the Zwicky Transient Facility archive as far back as 2018 October but were unable to locate any positive detections. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|