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Small Near-Earth Asteroids in the Palomar Transient Factory Survey: a Real-Time Streak-detection System

Waszczak, Adam and Prince, Thomas A. and Laher, Russ and Masci, Frank and Bue, Brian and Rebbapragada, Umaa and Barlow, Tom and Surace, Jason and Helou, George and Kulkarni, Shrinivas (2017) Small Near-Earth Asteroids in the Palomar Transient Factory Survey: a Real-Time Streak-detection System. Publications of the Astronomical Society of the Pacific, 129 (973). Art. No. 034402. ISSN 0004-6280. doi:10.1088/1538-3873/129/973/034402.

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Near-Earth asteroids (NEAs) in the 1–100 meter size range are estimated to be ~1,000 times more numerous than the ~15,000 currently cataloged NEAs, most of which are in the 0.5–10 kilometer size range. Impacts from 10–100 meter size NEAs are not statistically life-threatening, but may cause significant regional damage, while 1–10 meter size NEAs with low velocities relative to Earth are compelling targets for space missions. We describe the implementation and initial results of a real-time NEA-discovery system specialized for the detection of small, high angular rate (visually streaked) NEAs in Palomar Transient Factory (PTF) images. PTF is a 1.2-m aperture, 7.3 deg^2 field of view (FOV) optical survey designed primarily for the discovery of extragalactic transients (e.g., supernovae) in 60-second exposures reaching ~20.5 visual magnitude. Our real-time NEA discovery pipeline uses a machine-learned classifier to filter a large number of false-positive streak detections, permitting a human scanner to efficiently and remotely identify real asteroid streaks during the night. Upon recognition of a streaked NEA detection (typically within an hour of the discovery exposure), the scanner triggers follow-up with the same telescope and posts the observations to the Minor Planet Center for worldwide confirmation. We describe our 11 initial confirmed discoveries, all small NEAs that passed 0.3–15 lunar distances from Earth. Lastly, we derive useful scaling laws for comparing streaked-NEA-detection capabilities of different surveys as a function of their hardware and survey-pattern characteristics. This work most directly informs estimates of the streak-detection capabilities of the Zwicky Transient Facility (ZTF, planned to succeed PTF in 2017), which will apply PTF's current resolution and sensitivity over a 47-deg^2 FOV.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Prince, Thomas A.0000-0002-8850-3627
Laher, Russ0000-0003-2451-5482
Masci, Frank0000-0002-8532-9395
Bue, Brian0000-0002-7856-3570
Rebbapragada, Umaa0000-0002-2560-3495
Surace, Jason0000-0001-7291-0087
Helou, George0000-0003-3367-3415
Kulkarni, Shrinivas0000-0001-5390-8563
Additional Information:© 2017 The Astronomical Society of the Pacific. Received 2016 July 13; accepted 2016 September 11; published 2017 February 7. This work uses data obtained with the 1.2-m Samuel Oschin Telescope at Palomar Observatory as part of the Palomar Transient Factory project, a scientific collaboration among the California Institute of Technology, Columbia University, Las Cumbres Observatory, the Lawrence Berkeley National Laboratory, the National Energy Research Scientific Computing Center, the University of Oxford, and the Weizmann Institute of Science, and the Intermediate Palomar Transient Factory project, a scientific collaboration among the California Institute of Technology, Los Alamos National Laboratory, the University of Wisconsin, Milwaukee, the Oskar Klein Center, the Weizmann Institute of Science, the TANGO Program of the University System of Taiwan, and the Kavli Institute for the Physics and Mathematics of the universe. The authors thank Robert Jedicke and Quan-Zhi Ye for valuable comments on the paper, as well as the informative comments and suggestions by the referee. A. Waszczak has been supported in part by the W.M. Keck Institute for Space Studies (KISS) at Caltech and this work was part of his thesis research. The work presented in this paper was in part inspired by a workshop on an Asteroid Retrieval Mission organized and funded by KISS in 2010–2012. This work also was also supported by NASA JPL internal research and technology development funds. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Group:Infrared Processing and Analysis Center (IPAC), Keck Institute for Space Studies, Palomar Transient Factory, Astronomy Department
Funding AgencyGrant Number
Keck Institute for Space Studies (KISS)UNSPECIFIED
JPL Internal Research and Technology Development ProgramUNSPECIFIED
Subject Keywords:minor planets – asteroids: general
Issue or Number:973
Record Number:CaltechAUTHORS:20170206-134306305
Persistent URL:
Official Citation:Adam Waszczak et al 2017 PASP 129 034402
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:74089
Deposited By: Tony Diaz
Deposited On:06 Feb 2017 21:53
Last Modified:11 Nov 2021 05:24

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