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Initial Visible and Mid-IR Characterization of P/2019 LD₂ (ATLAS), an Active Transitioning Centaur Among the Trojans, with Hubble, Spitzer, ZTF, Keck, APO and GROWTH Imaging and Spectroscopy

Bolin, Bryce T. and Fernandez, Yanga R. and Lisse, Carey M. and Holt, Timothy R. and Lin, Zhong-Yi and Purdum, Josiah N. and Deshmukh, Kunal P. and Bauer, James M. and Bellm, Eric C. and Bodewits, Dennis and Burdge, Kevin B. and Carey, Sean J. and Copperwheat, Chris M. and Helou, George and Ho, Anna Y. Q. and Horner, Jonathan and van Roestel, Jan and Bhalerao, Varun and Chang, Chan-Kao and Chen, Christine and Hsu, Chen-Yen and Ip, Wing-Huen and Kasliwal, Mansi M. and Masci, Frank J. and Ngeow, Chow-Choong and Quimby, Robert and Burruss, Rick and Coughlin, Michael and Dekany, Richard and Delacroix, Alexandre and Drake, Andrew and Duev, Dmitry A. and Graham, Matthew and Hale, David and Kupfer, Thomas and Laher, Russ R. and Mahabal, Ashish and Mróz, Przemyslaw J. and Neill, James D. and Riddle, Reed and Rodriguez, Hector and Smith, Roger M. and Soumagnac, Maayane T. and Walters, Richard and Yan, Lin and Zolkower, Jeffry (2020) Initial Visible and Mid-IR Characterization of P/2019 LD₂ (ATLAS), an Active Transitioning Centaur Among the Trojans, with Hubble, Spitzer, ZTF, Keck, APO and GROWTH Imaging and Spectroscopy. . (Unpublished)

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We present visible and mid-infrared imagery and photometry of Jovian co-orbital comet P/2019 LD₂ (ATLAS) taken with Hubble Space Telescope/WFC3 on 2020 April 1, Spitzer Space Telescope/IRAC on 2020 January 25, Zwicky Transient Facility between 2019 April 9 and 2019 Nov 8 and the GROWTH telescope network from 2020 May to July, as well as visible spectroscopy from Keck/LRIS on 2020 August 19. Our observations indicate that LD₂ has a nucleus with radius 0.2-1.8 km assuming a 0.08 albedo and that the coma is dominated by ∼100 μ m-scale dust ejected at ∼1 m/s speeds with a ∼1" jet pointing in the SW direction. LD₂ experienced a total dust mass loss of ∼10⁸ kg and dust mass loss rate of ∼6 kg/s with Afρ/cross-section varying between ∼85 cm/125 km² and ∼200 cm/310 km² between 2019 April 9 and 2019 Nov 8. If the Afρ/cross-section increase remained constant, it implies that LD₂ has remained active since ∼2018 November when it came within 4.8 au of the Sun, a typical distance for comets to begin sublimation of H₂O. From our 4.5 μm Spitzer observations, we set a limit on CO/CO₂ gas production of ∼10²⁷/∼10²⁶ mol/s. Multiple bandpass photometry of LD₂ taken by the GROWTH network measured in a 10,000 km aperture provide color measurements of g-r = 0.59±0.03, r-i = 0.18±0.05, and i-z = 0.01±0.07, colors typical of comets. We set a spectroscopic upper limit to the production of H₂O gas of ∼80 kg/s. Improving the orbital solution for LD₂ with our observations, we determine that the long-term orbit of LD₂ is that of a typical Jupiter Family Comet having close encounters with Jupiter coming within ∼0.5 Hill radius in the last ∼3 y to within 0.8 Hill radius in ∼9 y and has a 95% chance of being ejected from the Solar System in < 10 Myr.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Bolin, Bryce T.0000-0002-4950-6323
Fernandez, Yanga R.0000-0003-1156-9721
Lisse, Carey M.0000-0002-9548-1526
Holt, Timothy R.0000-0003-0437-3296
Lin, Zhong-Yi0000-0003-3827-8991
Deshmukh, Kunal P.0000-0001-5253-3480
Bauer, James M.0000-0001-9542-0953
Bellm, Eric C.0000-0001-8018-5348
Bodewits, Dennis0000-0002-2668-7248
Burdge, Kevin B.0000-0002-7226-836X
Carey, Sean J.0000-0002-0221-6871
Copperwheat, Chris M.0000-0001-7983-8698
Helou, George0000-0003-3367-3415
Ho, Anna Y. Q.0000-0002-9017-3567
Horner, Jonathan0000-0002-1160-7970
van Roestel, Jan0000-0002-2626-2872
Bhalerao, Varun0000-0002-6112-7609
Chang, Chan-Kao0000-0003-1656-4540
Chen, Christine0000-0002-8382-0447
Ip, Wing-Huen0000-0002-3140-5014
Kasliwal, Mansi M.0000-0002-5619-4938
Masci, Frank J.0000-0002-8532-9395
Ngeow, Chow-Choong0000-0001-8771-7554
Quimby, Robert0000-0001-9171-5236
Coughlin, Michael0000-0002-8262-2924
Dekany, Richard0000-0002-5884-7867
Duev, Dmitry A.0000-0001-5060-8733
Graham, Matthew0000-0002-3168-0139
Kupfer, Thomas0000-0002-6540-1484
Laher, Russ R.0000-0003-2451-5482
Mahabal, Ashish0000-0003-2242-0244
Mróz, Przemyslaw J.0000-0001-7016-1692
Neill, James D.0000-0002-0466-1119
Riddle, Reed0000-0002-0387-370X
Smith, Roger M.0000-0001-7062-9726
Soumagnac, Maayane T.0000-0001-6753-1488
Walters, Richard0000-0002-1835-6078
Yan, Lin0000-0003-1710-9339
Additional Information:Based on observations with the NASA/ESA Hubble Space Telescope obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Univer- sities for Research in Astronomy, Incorporated, under NASA contracts NAS5-26555. Support for Program number (GO 16077) was provided through a grant from the STScI under NASA contract NAS5-26555. This work is based on observations made with the Spitzer Space Telescope, which was operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-1440341 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, the University of Washington, Deutsches Elektronen-Synchrotron and Humboldt University, Los Alamos National Laboratories, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, and Lawrence Berkeley National Laboratories. Operations are conducted by COO, IPAC, and UW. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. This work was supported by the GROWTH project funded by the National Science Foundation under PIRE Grant No 1545949. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. B.T.B., G.H. and F.J.M. acknowledge support from NASA with grant number 80NSSC19K0780. C.F. gratefully acknowledges the support of his research by the Heising-Simons Foundation (#2018-0907). M. W. Coughlin acknowledges support from the National Science Foundation with grant number PHY-2010970. This publication has made use of data collected at Lulin Observatory, partly supported by MoST grant 108-2112-M-008-001. C.C.N. thanks to the funding from MOST grant 104-2923-M-008-004-MY5. The authors would like to acknowledge the helpful discussion of P/2019 LD₂ with L. Woodney and Q.-Z. Ye. This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC, consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Facility: Hubble Space Telescope, Spitzer Space Telescope, Keck I Telescope, P48 Oschin Schmidt telescope/Zwicky Transient Facility, Apache Point Astrophysical Research Consortium 3.5 m telescope, Liverpool Telescope, Lulin Optical Telescope, Mount Laguna Observatory 40-inch Telescope Software: Small Body Python, ZChecker, LPipe
Group:Astronomy Department, Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility
Funding AgencyGrant Number
ZTF partner institutionsUNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
W. M. Keck FoundationUNSPECIFIED
Heising-Simons Foundation2018-0907
Ministry of Science and Technology (Taipei)108-2112-M-008-001
Ministry of Science and Technology (Taipei)104-2923-M-008-004-MY5
Gaia Multilateral AgreementUNSPECIFIED
Subject Keywords:minor planets, asteroids: individual (P/2019 LD2), temporarily captured orbiters, minimoons
Record Number:CaltechAUTHORS:20201203-151011869
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106895
Deposited By: George Porter
Deposited On:05 Dec 2020 02:05
Last Modified:05 Dec 2020 02:05

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