2018/02/14 by Fabio Reale, Javier Lopez-Santiago, Ettore Flaccomio +2 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Flare #Flare star #Light curve #Magnetic field #Magnetic reconnection #Plasma #Solar and Space Plasma Dynamics #Solar flare #Stars #Track (disk drive) #astro-ph.SR
paper · pdf · doi:10.3847/1538-4357/aaaf1f
25 pages, 8 figures, movie upon request, accepted for publication
arxiv created 2018/02/14 · openalex created_date 2018/02/23 · openalex publication_date 2018/03/20 · arxiv updated 2018/04/11 · openalex updated_date 2026/08/05
Abstract Pulsing X-ray emission tracks the plasma “echo” traveling in an extremely long magnetic tube that flares in an Orion pre-main sequence (PMS) star. On the Sun, flares last from minutes to a few hours and the longest-lasting ones typically involve arcades of closed magnetic tubes. Long-lasting X-ray flares are observed in PMS stars. Large-amplitude (∼20%), long-period (∼3 hr) pulsations are detected in the light curve of day-long flares observed by the Advanced CCD Imaging Spectrometer on-board Chandra from PMS stars in the Orion cluster. Detailed hydrodynamic modeling of two flares observed on V772 Ori and OW Ori shows that these pulsations may track the sloshing of plasma along a single long magnetic tube, triggered by a sufficiently short (∼1 hr) heat pulse. These magnetic tubes are ≥20 solar radii long, enough to connect the star with the surrounding disk.