Searching for Exotrojans in Pulsar Systems
Year: 2026
Type: article
Abstract: Trojan asteroids are found in the equilateral triangle Lagrange points of the Sun–Jupiter system in a great number, although they also exist less prolifically in other parts of the solar system. Despite up to planetary mass Trojans being predicted in extrasolar systems (i.e., exotrojans), they remain unconfirmed, although strong candidate evidence has emerged recently. For the first time, we extend the search for exotrojans to radio pulsars with low-mass (∼0.01 M ⊙ ) companions using accurately measured pulse times of arrival. With techniques developed for detecting the reflex motion of a star due to a librating Trojan, we place ∼1 M ⊕ upper mass constraints on potential exotrojans around eight pulsars observed in the NANOGrav 15 yr dataset. We find weak evidence consistent with ∼2–4 M J exotrojans in the PSR J0023+0923 and PSR J1705−1903 binary systems, although the signals likely have a different, unknown source. We also place a libration-independent upper mass constraint of ∼8 M J on exotrojans in the PSR J1641+8049 system by looking for an inconsistency between the times of superior conjunction as measured by optical light curves and those predicted by radio timing. These results offer initial observational constraints on the existence of exotrojans around pulsars, while their possible formation mechanisms remain unexplored.
Source: The Astrophysical Journal
Authors: Jackson D. Taylor, Emmanuel Fonseca, Lankeswar Dey, Sergey Zharikov, Aida Kirichenko, Joseph Glaser, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Paul R. Brook, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Deborah C. Good, Jeffrey S. Hazboun, Ross J. Jennings, Megan L. Jones, David L. Kaplan, Matthew Kerr, Michael T. Lam, T. Joseph W. Lazio, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Alexander McEwen, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Cherry Ng, David J. Nice, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Ann Schmiedekamp, Carl Schmiedekamp, Brent J. Shapiro-Albert, Ingrid H. Stairs, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Haley M. Wahl
Institutions: West Virginia University, Universidad Nacional Autónoma de México, University of Wisconsin–Milwaukee, University of North Carolina at Chapel Hill, Newcastle University, Goddard Space Flight Center, Widener University, University of Birmingham, United States Naval Research Laboratory, National Academy of Sciences, National Academies of Sciences, Engineering, and Medicine, University of British Columbia, George Mason University, National Radio Astronomy Observatory, Hillsdale College, Eureka Scientific, University of Maryland, College Park, University of Montana, Oregon State University, Naval Research Laboratory Space Science Division, Rochester Institute of Technology, Search for Extraterrestrial Intelligence, University of Toronto, Vanderbilt University, Curtin University, International Centre for Radio Astronomy Research, Lafayette College, Eötvös Loránd University, Arecibo Observatory, Texas Tech University, University of Puerto Rico-Mayaguez, Pennsylvania State University, United States Army, Leibniz University Hannover, Max Planck Institute for Gravitational Physics
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, West Virginia Space Grant Consortium, Canadian Institute for Advanced Research, University of Central Florida, West Virginia University, University of Toronto, Eötvös Loránd Tudományegyetem, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, Office of Naval Research, U.S. Naval Research Laboratory
Awards: NANOGrav@UPRM: Growing and Characterizing the NANOGrav Gravitational-Wave Detector, G118299772, NANOGrav Physics Frontier Center, MRI: Acquisition of Thorny Flat Next Generation Cluster for High-Performance Computing in West Virginia, WoU-MMA: Pulsar Timing Arrays Around the World CHIME in on Gravitational Waves, G3035126413, G3782671888, Astrophysics at the University of Birmingham - Consolidated grant 2022-2025, G4961910479, RII Track-1: Gravitational Wave Astronomy and the Appalachian Freshwater Initiative, Management and Operations of the Arecibo Observatory, Collaborative research: Completing the most sensitive low-frequency survey for radio pulsars and transients, G6451664670, G6508760690, The Construction of a Pulsar Interstellar Medium Array Detector, The NANOGrav Physics Frontiers Center
OpenAlex ID: W4415950357