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Post Info TOPIC: Sun 01.03.12


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RE: Sun 01.03.12
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Title: Sunspots rotation and magnetic transients associated with flares in NOAA AR 11429
Author: Jianchuan Zheng, Zhiliang Yang, Jianpeng Guo, Kaiming Guo, Hui Huang, Xuan Song, Weixing Wan

We analyze sunspots rotation and magnetic transients in NOAA AR 11429 during two X-class (X5.4 and X1.3) flares using the data from the Helioseismic and Magnetic Imager on board the \emph{Solar Dynamics Observatory}. A large leading sunspot with positive magnetic polarity rotated counterclockwise. As expected, the rotation was significantly affected by the two flares. The magnetic transients induced by the flares were clearly evident in the sunspots with negative polarity. They were moving across the sunspots with speed of order 3-7 km s^-1. Furthermore, the trend of magnetic flux evolution of these sunspots exhibited changes associated with the flares. These results may shed light on the understanding of the evolution of sunspots.

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Sunspot 11429
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Title: Analysis and modelling of recurrent solar flares observed with Hinode/EIS on March 9, 2012
Author: V. Polito, G. Del Zanna, G. Valori, E. Pariat, H. E. Mason, J. Dudik, M. Janvier

hree homologous C-class flares and one last M-class flare were observed by both the Solar Dynamics Observatory (SDO) and the Hinode EUV Imaging Spectrometer (EIS) in the AR 11429 on March 9, 2012. All the recurrent flares occurred within a short interval of time (less than 4 hours), showed very similar plasma morphology and were all confined, until the last one when a large-scale eruption occurred. The C-class flares are characterized by the appearance, at approximatively the same locations, of two bright and compact footpoint sources of \approx~3--10~MK evaporating plasma, and a semi-circular ribbon. During all the flares, the continuous brightening of a spine-like hot plasma (\approx~10~MK) structure is also observed. Spectroscopic observations with Hinode/EIS are used to measure and compare the blueshift velocities in the \fexxiii\ emission line and the electron number density at the flare footpoints for each flare. Similar velocities, of the order of 150--200~km~s^-1, are observed during the C2.0 and C4.7 confined flares, in agreement with the values reported by other authors in the study of the last M1.8 class flare. On the other hand, lower electron number densities and temperatures tend to be observed in flares with lower peak soft X-ray flux.In order to investigate the homologous nature of the flares, we performed a Non-Linear Force-Free Field (NLFFF) extrapolation of the 3D magnetic field configuration in the corona. The NLFFF extrapolation and the Quasi-Separatrix Layers (QSLs) provide the magnetic field context which explains the location of the kernels, spine-like and semi-circular brightenings observed in the (non-eruptive) flares. Given the absence of a coronal null point, we argue that the homologous flares were all generated by the continuous recurrence of bald patch reconnection.

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Solar Flare 07.03.12
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NASA'S Fermi Detects The Highest-Energy Light From A Solar Flare



During a powerful solar blast on March 7, NASA's Fermi Gamma-ray Space Telescope detected the highest-energy light ever associated with an eruption on the sun. The discovery heralds Fermi's new role as a solar observatory, a powerful new tool for understanding solar outbursts during the sun's maximum period of activity.
A solar flare is an explosive blast of light and charged particles. The powerful March 7 flare, which earned a classification of X5.4 based on the peak intensity of its X-rays, is the strongest eruption so far observed by Fermi's Large Area Telescope (LAT). The flare produced such an outpouring of gamma rays -- a form of light with even greater energy than X-rays -- that the sun briefly became the brightest object in the gamma-ray sky.

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Sun 11.03.12
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Sunspots 11429 and 11430 captured with a 100mm refractor (stopped down to ~80mm) and Vesta pro webcam. (DIY) Solar filter + Baader contrast filter + IR-cut filter.

The image is reversed.

(The ISS passed over the disk a few minutes later - I'll video it another time)



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Sun 08.03.12
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Sunspots 11429, 11430 and 11428 captured with a 100mm refractor and Vesta pro webcam. Solar filter + Baader contrast filter + IR-cut filter.

 

Sunspots 11429 and 11430 captured with a 100mm refractor and Vesta pro webcam. (DIY) Solar filter + Baader contrast filter + IR-cut filter + 2x Barlow lens.



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Posts: 131433
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Sun 07.03.12
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Sunspots 11429 and 11430 



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Sunspot 11429, 11430 and 11428


Sunspots 11429, 11430 and 11428 captured with a 100mm refractor and Vesta pro webcam. Solar filter + Baader contrast filter + IR-cut filter + 2x Barlow lens.
Sunspot 1429 has produced X-class solar flares.

Music is a homage to The Avengers and was generated with a vintage Amiga 1200 computer.



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Posts: 131433
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Sun 05.03.12
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Sunspots 11429, 11430 11428 and 11423 (+ small un-numbered group)


Monster Sunspot 11429 captured with a 100mm refractor and Vesta pro webcam. Solar filter + Baader contrast filter + IR-cut filter + 2x Barlow lens.

 Capture05_03_201213_14_31b.jpgCapture05_03_201213_11_35b.jpg
 Capture05_03_201213_08_43b.jpg Capture05_03_201213_13_40b.jpg
 Capture05_03_201213_10_50b.jpg Capture05_03_201213_12_55b.jpg
 Credit: SOHO/MDI 


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Posts: 131433
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Sun 04.03.12
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Sunspots 11429, 11428, 11427 and 11423

sun040312b.gif
Expand (144kb, 560 x 560)
Sunspot11429b.gif
Expand (408kb, 1024 x 768)

Credit: SOHO/MDI



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RE: Sun 03.03.12
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A new sunspot has emerged over the Sun's eastern limb.

Sun030312b.jpg
Expand (140kb, 560 x 560)
Credit: SOHO/MDI



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