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Impact of the SpaceX Starlink Satellites on the Zwicky Transient Facility Survey Observations

Mróz, Przemek and Otarola, Angel and Prince, Thomas A. and Dekany, Richard and Duev, Dmitry A. and Graham, Matthew J. and Groom, Steven L. and Masci, Frank J. and Medford, Michael S. (2022) Impact of the SpaceX Starlink Satellites on the Zwicky Transient Facility Survey Observations. Astrophysical Journal Letters, 924 (2). Art. No. L30. ISSN 2041-8205. doi:10.3847/2041-8213/ac470a.

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There is a growing concern about an impact of low-Earth-orbit (LEO) satellite constellations on ground-based astronomical observations, in particular, on wide-field surveys in the optical and infrared. The Zwicky Transient Facility (ZTF), thanks to the large field of view of its camera, provides an ideal setup to study the effects of LEO megaconstellations—such as SpaceX’s Starlink—on astronomical surveys. Here, we analyze the archival ZTF observations collected between 2019 November and 2021 September and find 5301 satellite streaks that can be attributed to Starlink satellites. We find that the number of affected images is increasing with time as SpaceX deploys more satellites. Twilight observations are particularly affected—a fraction of streaked images taken during twilight has increased from less than 0.5% in late 2019 to 18% in 2021 August. We estimate that once the size of the Starlink constellation reaches 10,000, essentially all ZTF images taken during twilight may be affected. However, despite the increase in satellite streaks observed during the analyzed period, the current science operations of ZTF are not yet strongly affected. We also find that redesigning Starlink satellites (by installing visors intended to block sunlight from reaching the satellite antennas to prevent reflection) reduces their brightness by a factor of 4.6 ± 0.1 with respect to the original design in g, r, and i bands.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Mróz, Przemek0000-0001-7016-1692
Otarola, Angel0000-0002-9789-2564
Prince, Thomas A.0000-0002-8850-3627
Dekany, Richard0000-0002-5884-7867
Duev, Dmitry A.0000-0001-5060-8733
Graham, Matthew J.0000-0002-3168-0139
Groom, Steven L.0000-0001-5668-3507
Masci, Frank J.0000-0002-8532-9395
Medford, Michael S.0000-0002-7226-0659
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 December 10; revised 2021 December 15; accepted 2021 December 25; published 2022 January 14. We thank Olivier Hainaut and Radek Poleski for discussions and their comments on the manuscript. We thank Dr. T. S. Kelso of CelesTrak for maintaining the database of Starlink TLE data. 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-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum and Northwestern University. Operations are conducted by COO, IPAC, and UW.
Group:Astronomy Department, Infrared Processing and Analysis Center (IPAC), Zwicky Transient Facility
Funding AgencyGrant Number
ZTF partner institutionsUNSPECIFIED
Subject Keywords:Artificial satellites; Astronomical site protection; Night sky brightness; Ground-based astronomy; Observational astronomy; Sky surveys
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Artificial satellites (68); Astronomical site protection (94); Night sky brightness (1112); Ground-based astronomy (686); Observational astronomy (1145); Sky surveys (1464)
Record Number:CaltechAUTHORS:20220118-993586000
Persistent URL:
Official Citation:Przemek Mróz et al 2022 ApJL 924 L30
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112952
Deposited By: George Porter
Deposited On:19 Jan 2022 16:01
Last Modified:19 Jan 2022 16:01

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