2011/06/07 by V. S. Dhillon, T. R. Marsh, S. P. Littlefair +9 · 2 citations
Earth and Planetary Sciences · Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Context (archaeology) #Gamma ray #High-pressure geophysics and materials #Infrared #Light curve #Magnetar #Neutron star #Photometry (optics) #Physics #Pulsars and Gravitational Waves Research #Stars #astro-ph.SR
paper · pdf · doi:10.1111/j.1745-3933.2011.01088.x
5 pages, 3 figures, accepted for publication in MNRAS Letters
arxiv created 2011/06/07 · openalex publication_date 2011/06/30 · arxiv updated 2015/05/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
ABSTRACT We present high-speed optical photometry of the soft gamma repeater SGR 0501+4516, obtained with ULTRACAM on two consecutive nights approximately 4 months after the source was discovered via its gamma-ray bursts. We detect SGR 0501+4516 at a magnitude of i′= 24.4 ± 0.1. We present the first measurement of optical pulsations from a SGR, deriving a period of 5.7622 ± 0.0003 s, in excellent agreement with the X-ray spin period of the neutron star. We compare the morphologies of the optical pulse profile with the X-ray and infrared pulse profiles; we find that the optical, infrared and harder X-rays share similar double-peaked morphologies, but the softer X-rays exhibit only a single-peaked morphology, indicative of a different origin. The optical pulsations appear to be in phase with the X-ray pulsations and exhibit a root-mean-square pulsed fraction of 52 ± 7 per cent, approximately a factor of 2 greater than in the X-rays. Our results find a natural explanation within the context of the magnetar model for SGRs.