--- OA_type: closed access _id: '18867' abstract: - lang: eng text: 'In an accreting X-ray pulsar, a neutron star accretes matter from a companion star through an accretion disk. The magnetic field of the rotating neutron star disrupts the inner edge of the disk, funnelling the gas to flow onto the poles on its surface. Hercules X-1 is a prototypical persistent X-ray pulsar about 7 kpc from Earth. Its emission varies on three distinct timescales: the neutron star rotates every 1.2 s, it is eclipsed by its companion each 1.7 d, and the system exhibits a superorbital period of 35 d, which has remained stable since its discovery. Several lines of evidence point to the source of this variation as the precession of the accretion disk or that of the neutron star. Despite the many hints over the past 50 yr, the precession of the neutron star itself has yet not been confirmed or refuted. X-ray polarization measurements (probing the spin geometry of Her X-1) with the Imaging X-ray Polarimetry Explorer suggest that free precession of the neutron star crust sets the 35 d period; this has the important implication that its crust is somewhat asymmetric by a few parts per ten million.' article_processing_charge: No article_type: original author: - first_name: Jeremy full_name: Heyl, Jeremy last_name: Heyl - first_name: Victor full_name: Doroshenko, Victor last_name: Doroshenko - first_name: Denis full_name: González-Caniulef, Denis last_name: González-Caniulef - first_name: Ilaria full_name: Caiazzo, Ilaria id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d last_name: Caiazzo orcid: 0000-0002-4770-5388 - first_name: Juri full_name: Poutanen, Juri last_name: Poutanen - first_name: Alexander full_name: Mushtukov, Alexander last_name: Mushtukov - first_name: Sergey S. full_name: Tsygankov, Sergey S. last_name: Tsygankov - first_name: Demet full_name: Kirmizibayrak, Demet last_name: Kirmizibayrak - 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first_name: Alessio full_name: Trois, Alessio last_name: Trois - first_name: Roberto full_name: Turolla, Roberto last_name: Turolla - first_name: Jacco full_name: Vink, Jacco last_name: Vink - first_name: Martin C. full_name: Weisskopf, Martin C. last_name: Weisskopf - first_name: Kinwah full_name: Wu, Kinwah last_name: Wu - first_name: Fei full_name: Xie, Fei last_name: Xie - first_name: Silvia full_name: Zane, Silvia last_name: Zane citation: ama: Heyl J, Doroshenko V, González-Caniulef D, et al. Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization. Nature Astronomy. 2024;8:1047-1053. doi:10.1038/s41550-024-02295-8 apa: Heyl, J., Doroshenko, V., González-Caniulef, D., Caiazzo, I., Poutanen, J., Mushtukov, A., … Zane, S. (2024). Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization. Nature Astronomy. Springer Nature. https://doi.org/10.1038/s41550-024-02295-8 chicago: Heyl, Jeremy, Victor Doroshenko, Denis González-Caniulef, Ilaria Caiazzo, Juri Poutanen, Alexander Mushtukov, Sergey S. Tsygankov, et al. “Complex Rotational Dynamics of the Neutron Star in Hercules X-1 Revealed by X-Ray Polarization.” Nature Astronomy. Springer Nature, 2024. https://doi.org/10.1038/s41550-024-02295-8. ieee: J. Heyl et al., “Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization,” Nature Astronomy, vol. 8. Springer Nature, pp. 1047–1053, 2024. ista: Heyl J et al. 2024. Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization. Nature Astronomy. 8, 1047–1053. mla: Heyl, Jeremy, et al. “Complex Rotational Dynamics of the Neutron Star in Hercules X-1 Revealed by X-Ray Polarization.” Nature Astronomy, vol. 8, Springer Nature, 2024, pp. 1047–53, doi:10.1038/s41550-024-02295-8. short: J. Heyl, V. Doroshenko, D. González-Caniulef, I. Caiazzo, J. Poutanen, A. Mushtukov, S.S. Tsygankov, D. Kirmizibayrak, M. Bachetti, G.G. Pavlov, S.V. Forsblom, C. Malacaria, V.F. Suleimanov, I. Agudo, L.A. Antonelli, L. Baldini, W.H. Baumgartner, R. Bellazzini, S. Bianchi, S.D. Bongiorno, R. Bonino, A. Brez, N. Bucciantini, F. Capitanio, S. Castellano, E. Cavazzuti, C.-T. Chen, S. Ciprini, E. Costa, A. De Rosa, E. Del Monte, L. Di Gesu, N. Di Lalla, A. Di Marco, I. Donnarumma, M. Dovčiak, S.R. Ehlert, T. Enoto, Y. Evangelista, S. Fabiani, R. Ferrazzoli, J.A. Garcia, S. Gunji, K. Hayashida, W. Iwakiri, S.G. Jorstad, P. Kaaret, V. Karas, F. Kislat, T. Kitaguchi, J.J. Kolodziejczak, H. Krawczynski, F. La Monaca, L. Latronico, I. Liodakis, S. Maldera, A. Manfreda, F. Marin, A. Marinucci, A.P. Marscher, H.L. Marshall, F. Massaro, G. Matt, I. Mitsuishi, T. Mizuno, F. Muleri, M. Negro, C.-Y. Ng, S.L. O’Dell, N. Omodei, C. Oppedisano, A. Papitto, A.L. Peirson, M. Perri, M. Pesce-Rollins, P.-O. Petrucci, M. Pilia, A. Possenti, S. Puccetti, B.D. Ramsey, J. Rankin, A. Ratheesh, O.J. Roberts, R.W. Romani, C. Sgrò, P. Slane, P. Soffitta, G. Spandre, D.A. Swartz, T. Tamagawa, F. Tavecchio, R. Taverna, Y. Tawara, A.F. Tennant, N.E. Thomas, F. Tombesi, A. Trois, R. Turolla, J. Vink, M.C. Weisskopf, K. Wu, F. Xie, S. Zane, Nature Astronomy 8 (2024) 1047–1053. date_created: 2025-01-21T15:35:17Z date_published: 2024-08-01T00:00:00Z date_updated: 2025-01-27T10:52:16Z day: '01' doi: 10.1038/s41550-024-02295-8 extern: '1' intvolume: ' 8' language: - iso: eng month: '08' oa_version: None page: 1047-1053 publication: Nature Astronomy publication_identifier: issn: - 2397-3366 publication_status: published publisher: Springer Nature quality_controlled: '1' scopus_import: '1' status: public title: Complex rotational dynamics of the neutron star in Hercules X-1 revealed by X-ray polarization type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 8 year: '2024' ...