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A Twilight Search for Atiras, Vatiras, and Co-orbital Asteroids: Preliminary Results

Ye, Quanzhi and Masci, Frank J. and Ip, Wing-Huen and Prince, Thomas A. and Helou, George and Farnocchia, Davide and Bellm, Eric C. and Dekany, Richard and Graham, Matthew J. and Kulkarni, Shrinivas R. and Kupfer, Thomas and Mahabal, Ashish and Ngeow, Chow-Choong and Reiley, Daniel J. and Soumagnac, Maayane T. (2020) A Twilight Search for Atiras, Vatiras, and Co-orbital Asteroids: Preliminary Results. Astronomical Journal, 159 (2). Art. No. 70. ISSN 1538-3881. doi:10.3847/1538-3881/ab629c.

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Near-Earth objects (NEOs) that orbit the Sun on or within Earth's orbit are tricky to detect for Earth-based observers due to their proximity to the Sun in the sky. These small bodies hold clues to the dynamical history of the inner solar system as well as the physical evolution of planetesimals in extreme environments. Populations in this region include the Atira and Vatira asteroids, as well as Venus and Earth co-orbital asteroids. Here we present a twilight search for these small bodies, conducted using the 1.2 m Oschin Schmidt and the Zwicky Transient Facility (ZTF) camera at Palomar Observatory. The ZTF twilight survey operates at solar elongations down to 35° with a limiting magnitude of r = 19.5. During a total of 40 evening sessions and 62 morning sessions conducted between 2018 November 15 and 2019 June 23, we detected six Atiras, including two new discoveries, 2019 AQ₃ and 2019 LF₆, but no Vatiras or Earth/Venus co-orbital asteroids. NEO population models show that these new discoveries are likely only the tip of the iceberg, with the bulk of the population yet to be found. The population models also suggest that we have only detected 5%–7% of the H < 20 Atira population over the seven month survey. Co-orbital asteroids are smaller in diameter and require deeper surveys. A systematic and efficient survey of the near-Sun region will require deeper searches and/or facilities that can operate at small solar elongations.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Ye, Quanzhi0000-0002-4838-7676
Masci, Frank J.0000-0002-8532-9395
Ip, Wing-Huen0000-0002-3140-5014
Prince, Thomas A.0000-0002-8850-3627
Helou, George0000-0003-3367-3415
Farnocchia, Davide0000-0003-0774-884X
Bellm, Eric C.0000-0001-8018-5348
Graham, Matthew J.0000-0002-3168-0139
Kulkarni, Shrinivas R.0000-0001-5390-8563
Kupfer, Thomas0000-0002-6540-1484
Mahabal, Ashish0000-0003-2242-0244
Ngeow, Chow-Choong0000-0001-8771-7554
Soumagnac, Maayane T.0000-0001-6753-1488
Additional Information:© 2020 The American Astronomical Society. Received 2019 October 6; revised 2019 December 11; accepted 2019 December 12; published 2020 January 23. We thank the anonymous referee for comments. Q.-Z.Y. acknowledges support by the Global Relay of Observatories Watching Transients Happen (GROWTH) project funded by the National Science Foundation Partnership in International Research and Education (PIRE) program under grant No. 1545949. We also thank Dave Tholen for discussion in the early phase of ZTF-TS and Bryce Bolin for comments. The work of W.-H.I. was supported in part by grant No. 107-2119-M-008-012 of MOST, Taiwan, and grant No. 119/2017/A3 of FCDT of Macau, MSAR. D.F. conducted this research at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Based on observations obtained with the Samuel Oschin Telescope 48 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 Caltech Optical Observatories, Infrared Processing and Analysis Center, and the University of Washington. Facility: PO:1.2m. - Software: astcheck, Matplotlib (Hunter 2007), NEOPOP (Granvik et al. 2018), sbpy (Mommert et al. 2018).
Group:Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility, Astronomy Department
Funding AgencyGrant Number
Ministry of Science and Technology (Taipei)107-2119-M-008-012
Macao Science and Technology Development Fund (FDCT)119/2017/A3
Subject Keywords:Atira group; Near-Earth objects; Earth trojans; Sky surveys
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Atira group (111); Near-Earth objects (1092); Earth trojans (438); Sky surveys (1464)
Record Number:CaltechAUTHORS:20200124-134730965
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Official Citation:Quanzhi Ye et al 2020 AJ 159 70
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100903
Deposited By: Tony Diaz
Deposited On:25 Jan 2020 03:33
Last Modified:16 Nov 2021 17:57

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