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Post Info TOPIC: Sun 04.09.11


L

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RE: Sun 04.09.11
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Title: A solar eruption driven by rapid sunspot rotation
Author: Guiping Ruan, Yao Chen, Shuo Wang, Hongqi Zhang, Gang Li, Ju Jing, Jiangtao Su, Xing Li, Haiqing Xu, Guohui Du, Haimin Wang

We present the observation of a major solar eruption that is associated with fast sunspot rotation. The event includes a sigmoidal filament eruption, a coronal mass ejection, and a GOES X2.1 flare from NOAA active region 11283. The filament and some overlying arcades were partially rooted in a sunspot. The sunspot rotated at ~10 per hour rate during a period of 6 hours prior to the eruption. In this period, the filament was found to rise gradually along with the sunspot rotation. Based on the HMI observation, for an area along the polarity inversion line underneath the filament, we found gradual pre-eruption decreases of both the mean strength of the photospheric horizontal field (Bh) and the mean inclination angle between the vector magnetic field and the local radial (or vertical) direction. These observations are consistent with the pre-eruption gradual rising of the filament-associated magnetic structure. In addition, according to the Non-Linear Force-Free-Field reconstruction of the coronal magnetic field, a pre-eruption magnetic flux rope structure is found to be in alignment with the filament, and a considerable amount of magnetic energy was transported to the corona during the period of sunspot rotation. Our study provides evidences that in this event sunspot rotation plays an important role in twisting, energizing, and destabilizing the coronal filament-flux rope system, and led to the eruption. We also propose that the pre-event evolution of Bh may be used to discern the driving mechanism of eruptions.

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L

Posts: 131433
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Sun 08.09.11
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Sunspot 11283

Sun080911b.jpg
Expand(140kb, 560 x 560)
Credit: SOHO/MDI



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L

Posts: 131433
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Sun 07.09.11
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X1.8 X-ray event recorded at 22:32 UTC, 7th September, 2011.



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L

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New Sunspot 11283

Sun070911b.jpg
Expand(133kb, 560 x 560)
Credit: SOHO/MDI

Ed ~ these three large sunspots are easily visible in small telescopes (above 30mm) fitted with suitable solar filters



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L

Posts: 131433
Date:
Sun 05.09.11
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Moderate Solar Flare Eruption

At 9:35 PM ET on September 5, 2011, the sun emitted an Earth-directed M5.3 class flare as measured by the GOES satellite. The flare erupted from a region of the sun that appears close to dead center from Earth's perspective, an active region designated number 1283. The flare caused a slight increase of solar energetic protons some 26,000 miles above Earth's surface.
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L

Posts: 131433
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RE: Sun 06.09.11
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A new sunspot is emerging over the Suns eastern limb.

Sun060911b.jpg
Expand(128kb, 560 x 560)
Credit: SOHO/MDI



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L

Posts: 131433
Date:
Sun 04.09.11
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Sunspots 11287, 11283, 11281, 11282, 11277, and 11280.

sun040911b.jpg
Expand(189kb, 560 x 560)
Credit: SOHO/MDI



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