* Astronomy

Members Login
Post Info TOPIC: Sun 05.10.11


L

Posts: 131433
Date:
Sunspot 11305
Permalink  
 


Title: Study of the recurring dimming region detected at AR 11305 using the Coronal Dimming Tracker (CoDiT)
Authors: Larisza D. Krista, Alysha A. Reinard

We present a new approach to coronal dimming detection using the COronal DImming Tracker tool (CODIT), which was found to be successful in locating and tracking multiple dimming regions. This tool, an extension of a previously developed coronal hole tracking software, allows us to study the properties and the spatial evolution of dimming regions at high temporal and spatial cadence from the time of their appearance to their disappearance. We use the Solar Dynamics Observatory/Atmospheric Imaging Assembly 193 A wavelength observations and Helioseismic and Magnetic Imager to study dimmings. As a demonstration of the detection technique we analysed six recurrences of a dimming observed near AR 11305 between 2011 September 29 and October 2. The dimming repeatedly ap- peared and formed in a similar way, first expanding then shrinking and occasionally stabilising in the same location until the next eruption. The dimming areas were studied in conjunction with the corresponding flare magnitudes and coronal mass ejection (CME) masses. These properties were found to follow a similar trend during the observation period, which is consistent with the idea that the magnitude of the eruption and the CME mass affect the relative sizes of the consecutive dimmings. We also present a hypothesis to explain the evolution of the recurrent single dimming through interchange reconnection. This process would accommodate the relocation of quasi-open magnetic field lines and hence allow the CME flux rope footpoint (the dimming) to expand into quiet Sun regions. By relating the properties of dimmings, flares, and CMEs we improve our understanding of the magnetic field reconfiguration caused by reconnection.

Read more (3548kb, PDF)



__________________


L

Posts: 131433
Date:
Sun 05.10.11
Permalink  
 


Sunspots 11312, 11309, 11311, 11310, 11307, 11306, 11305 and 11302.

Sun051011b.gif
Expand (140kb, 560 x 560)
Credit: SOHO/MDI



__________________
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard