Letter to the Editor

Bright unintended electromagnetic radiation from second-generation Starlink satellites

¹ ASTRON, Netherlands Institute for Radio Astronomy, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo, The Netherlands
² Square Kilometre Array Observatory, Lower Withington, Macclesfield, Cheshire SK11 9FT, United Kingdom
³ European Science Foundation, Committee on Radio Astronomy Frequencies, 1, quai Lezay Marnésia BP 90015, F-67080 Strasbourg Cedex, France
⁴ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁵ Department of Physics and Electronics, Rhodes University, PO Box 94 Makhanda 6140, South Africa
⁶ LESIA, Observatoire de Paris, Université PSL, CNRS, 5 place Jules Janssen, 92195 Meudon, France

Received: 9 August 2024
Accepted: 29 August 2024

Abstract

We report on the detection of unintended electromagnetic radiation (UEMR) from the second-generation of Starlink satellites. Observations with the LOFAR radio telescope between 10 to 88 MHz and 110 to 188 MHz show broadband emission covering the frequency ranges from 40 to 70 MHz and 110 to 188 MHz from the v2-Mini and v2-Mini Direct-to-Cell Starlink satellites. The spectral power flux density of this broadband UEMR varies from satellite to satellite, with values ranging from 15 to 1300 Jy, between 56 and 66 MHz, and from 2 to 100 Jy over two distinct 8 MHz frequency ranges centered at 120 and 161 MHz. We compared the detected power flux densities of this UEMR to that emitted by the first generation v1.0 and v1.5 Starlink satellites. When correcting for the observed satellite distances, we find that the second-generation satellites emit UEMR that is up to a factor of 32 stronger compared to the first generation. The calculated electric field strengths of the detected UEMR exceed typical electromagnetic compatibility standards used for commercial electronic devices as well as recommended emission thresholds from the Radiocommunication Sector of the International Telecommunications Union (ITU-R) aimed at protecting the 150.05–153 MHz frequency range allocated to radio astronomy. We characterize the properties of the detected UEMR with the aim of assisting the satellite operator with the identification of the cause of the UEMR.