Preflare X-ray Pulsations with Sources Outside the Main Flare Active Region

I. V. Zimovets, I. N. Sharykin, T. I. Kaltman, A. G. Stupishin, B. A. Nizamov

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Abstract: Earlier, we showed that according to the nature of the location of sources of preflare X-ray pulsations relative to the main solar flare, events are divided into at least two types: in type I events, the sources of pulsations and the main flare are in the same active region (AR) and in type II events they are in different regions. This paper presents an analysis of a type II event in which, according to data from the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) space observatory, X-ray sources of preflare quasi-periodic pulsations (with a period P = 1.5 ± 0.1 min), which began at ~1802 UT, were located in AR 11 884 in the Western Hemisphere, and the sources of the main flare M1.0 SOL2013-11-05T18:08 were located in AR 11 890 in the Eastern Hemisphere. The pulsations were also observed with the Gamma-Ray Burst Monitor (GBM) aboard the Fermi space observatory and the X-Ray Sensor (XRS) aboard the Geostationary Operational Environmental Satellite (GOES), excluding the possibility of their artificial origin. According to the data of the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO) in the extreme ultraviolet range, it was found that the sources of pulsations were located at the base of coronal jets that flowed out at velocities of ~100–1500 km/s. The distance between AR 11 884 and AR 11 890 was ~1.4 R S. It would take ~17–250 min for the jet plasma to reach AR 11 890, which is much longer than the time interval between the onset of pulsations (jets) and the flare (~6 min). No loops connecting AR 11 884 and AR 11 890 were observed in the corona. Moreover, no connection of these regions by magnetic field lines extrapolated from the photosphere to the corona in the potential approximation was found. These arguments indicate that the jets (and associated pulsations) could not be the trigger for the flare. Thus, a vivid example of an event is presented in which there was no physical connection between preflare X-ray pulsations (and jets) and the flare that followed them. This event demonstrates the importance of spatially resolved observations in the study of pulsations on the Sun and stars.

Original languageEnglish (US)
Pages (from-to)513-526
Number of pages14
JournalGeomagnetism and Aeronomy
Issue number5
StatePublished - Sep 2023
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Space and Planetary Science


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