Characterization of Temporarily Captured Minimoon 2020 CD3by Keck Time-resolved Spectrophotometry

Bryce T. Bolin; Christoffer Fremling; Timothy R. Holt; Matthew J. Hankins; Tomás Ahumada; Shreya Anand; Varun Bhalerao; Kevin B. Burdge; Chris M. Copperwheat; Michael Coughlin; Kunal P. Deshmukh; Kishalay De; Mansi M. Kasliwal; Alessandro Morbidelli; Josiah N. Purdum; Robert Quimby; Dennis Bodewits; Chan Kao Chang; Wing Huen Ip; Chen Yen Hsu; Russ R. Laher; Zhong Yi Lin; Carey M. Lisse; Frank J. Masci; Chow Choong Ngeow; Hanjie Tan; Chengxing Zhai; Rick Burruss; Richard Dekany; Alexandre Delacroix; Dmitry A. Duev; Matthew Graham; David Hale; Shrinivas R. Kulkarni; Thomas Kupfer; Ashish Mahabal; Przemyslaw J. Mróz; James D. Neill; Reed Riddle; Hector Rodriguez; Roger M. Smith; Maayane T. Soumagnac; Richard Walters; Lin Yan; Jeffry Zolkower

doi:10.3847/2041-8213/abae69

Characterization of Temporarily Captured Minimoon 2020 CD₃by Keck Time-resolved Spectrophotometry

Bryce T. Bolin, Christoffer Fremling, Timothy R. Holt, Matthew J. Hankins, Tomás Ahumada, Shreya Anand, Varun Bhalerao, Kevin B. Burdge, Chris M. Copperwheat, Michael Coughlin, Kunal P. Deshmukh, Kishalay De, Mansi M. Kasliwal, Alessandro Morbidelli, Josiah N. Purdum, Robert Quimby, Dennis Bodewits, Chan Kao Chang, Wing Huen Ip, Chen Yen HsuRuss R. Laher, Zhong Yi Lin, Carey M. Lisse, Frank J. Masci, Chow Choong Ngeow, Hanjie Tan, Chengxing Zhai, Rick Burruss, Richard Dekany, Alexandre Delacroix, Dmitry A. Duev, Matthew Graham, David Hale, Shrinivas R. Kulkarni, Thomas Kupfer, Ashish Mahabal, Przemyslaw J. Mróz, James D. Neill, Reed Riddle, Hector Rodriguez, Roger M. Smith, Maayane T. Soumagnac, Richard Walters, Lin Yan, Jeffry Zolkower

Graduate Institute of Astronomy

Research output: Contribution to journal › Article › peer-review

14 Scopus citations

Abstract

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.

Original language	English
Article number	L45
Journal	Astrophysical Journal Letters
Volume	900
Issue number	2
DOIs	https://doi.org/10.3847/2041-8213/abae69
State	Published - 10 Sep 2020

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Bolin, B. T., Fremling, C., Holt, T. R., Hankins, M. J., Ahumada, T., Anand, S., Bhalerao, V., Burdge, K. B., Copperwheat, C. M., Coughlin, M., Deshmukh, K. P., De, K., Kasliwal, M. M., Morbidelli, A., Purdum, J. N., Quimby, R., Bodewits, D., Chang, C. K., Ip, W. H., ... Zolkower, J. (2020). Characterization of Temporarily Captured Minimoon 2020 CD₃by Keck Time-resolved Spectrophotometry. Astrophysical Journal Letters, 900(2), Article L45. https://doi.org/10.3847/2041-8213/abae69

@article{21d296d78db54974b90bfb2863abc881,

title = "Characterization of Temporarily Captured Minimoon 2020 CD3by Keck Time-resolved Spectrophotometry",

abstract = "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.",

author = "Bolin, {Bryce T.} and Christoffer Fremling and Holt, {Timothy R.} and Hankins, {Matthew J.} and Tom{\'a}s Ahumada and Shreya Anand and Varun Bhalerao and Burdge, {Kevin B.} and Copperwheat, {Chris M.} and Michael Coughlin and Deshmukh, {Kunal P.} and Kishalay De and Kasliwal, {Mansi M.} and Alessandro Morbidelli and Purdum, {Josiah N.} and Robert Quimby and Dennis Bodewits and Chang, {Chan Kao} and Ip, {Wing Huen} and Hsu, {Chen Yen} and Laher, {Russ R.} and Lin, {Zhong Yi} and Lisse, {Carey M.} and Masci, {Frank J.} and Ngeow, {Chow Choong} and Hanjie Tan and Chengxing Zhai and Rick Burruss and Richard Dekany and Alexandre Delacroix and Duev, {Dmitry A.} and Matthew Graham and David Hale and Kulkarni, {Shrinivas R.} and Thomas Kupfer and Ashish Mahabal and Mr{\'o}z, {Przemyslaw J.} and Neill, {James D.} and Reed Riddle and Hector Rodriguez and Smith, {Roger M.} and Soumagnac, {Maayane T.} and Richard Walters and Lin Yan and Jeffry Zolkower",

year = "2020",

month = sep,

day = "10",

doi = "10.3847/2041-8213/abae69",

language = "???core.languages.en_GB???",

volume = "900",

journal = "Astrophysical Journal Letters",

issn = "2041-8205",

number = "2",

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Bolin, BT, Fremling, C, Holt, TR, Hankins, MJ, Ahumada, T, Anand, S, Bhalerao, V, Burdge, KB, Copperwheat, CM, Coughlin, M, Deshmukh, KP, De, K, Kasliwal, MM, Morbidelli, A, Purdum, JN, Quimby, R, Bodewits, D, Chang, CK, Ip, WH, Hsu, CY, Laher, RR, Lin, ZY, Lisse, CM, Masci, FJ, Ngeow, CC, Tan, H, Zhai, C, Burruss, R, Dekany, R, Delacroix, A, Duev, DA, Graham, M, Hale, D, Kulkarni, SR, Kupfer, T, Mahabal, A, Mróz, PJ, Neill, JD, Riddle, R, Rodriguez, H, Smith, RM, Soumagnac, MT, Walters, R, Yan, L & Zolkower, J 2020, 'Characterization of Temporarily Captured Minimoon 2020 CD₃by Keck Time-resolved Spectrophotometry', Astrophysical Journal Letters, vol. 900, no. 2, L45. https://doi.org/10.3847/2041-8213/abae69

TY - JOUR

T1 - Characterization of Temporarily Captured Minimoon 2020 CD3by Keck Time-resolved Spectrophotometry

AU - Bolin, Bryce T.

AU - Fremling, Christoffer

AU - Holt, Timothy R.

AU - Hankins, Matthew J.

AU - Ahumada, Tomás

AU - Anand, Shreya

AU - Bhalerao, Varun

AU - Burdge, Kevin B.

AU - Copperwheat, Chris M.

AU - Coughlin, Michael

AU - Deshmukh, Kunal P.

AU - De, Kishalay

AU - Kasliwal, Mansi M.

AU - Morbidelli, Alessandro

AU - Purdum, Josiah N.

AU - Quimby, Robert

AU - Bodewits, Dennis

AU - Chang, Chan Kao

AU - Ip, Wing Huen

AU - Hsu, Chen Yen

AU - Laher, Russ R.

AU - Lin, Zhong Yi

AU - Lisse, Carey M.

AU - Masci, Frank J.

AU - Ngeow, Chow Choong

AU - Tan, Hanjie

AU - Zhai, Chengxing

AU - Burruss, Rick

AU - Dekany, Richard

AU - Delacroix, Alexandre

AU - Duev, Dmitry A.

AU - Graham, Matthew

AU - Hale, David

AU - Kulkarni, Shrinivas R.

AU - Kupfer, Thomas

AU - Mahabal, Ashish

AU - Mróz, Przemyslaw J.

AU - Neill, James D.

AU - Riddle, Reed

AU - Rodriguez, Hector

AU - Smith, Roger M.

AU - Soumagnac, Maayane T.

AU - Walters, Richard

AU - Yan, Lin

AU - Zolkower, Jeffry

PY - 2020/9/10

Y1 - 2020/9/10

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=85091827843&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/abae69

DO - 10.3847/2041-8213/abae69

M3 - 期刊論文

AN - SCOPUS:85091827843

SN - 2041-8205

VL - 900

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

IS - 2

M1 - L45

ER -

Characterization of Temporarily Captured Minimoon 2020 CD3by Keck Time-resolved Spectrophotometry

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Characterization of Temporarily Captured Minimoon 2020 CD₃by Keck Time-resolved Spectrophotometry