TY - GEN
T1 - Flare induced penumbra formation in the sunspot of NOAA 10838
AU - Padinhatteeri, Sreejith
AU - Sankarasubramanian, K.
PY - 2010/8
Y1 - 2010/8
N2 - We have observed formation of penumbrae on a pore in the active region NOAA10838 using Dunn Solar Telescope at NSO,Sunpot,USA. Simultaneous observations using different instruments (DLSP,UBF,Gband and CaK) provide us with vector magnetic field at photosphere, intensity images and Doppler velocity at different heights from photosphere to chromosphere. Results from our analysis of this particular data-set suggests that penumbrae are formed as a result of relaxation of magnetic field due to a flare happening at the same time. Images in Hα show the flare (C 2.9 as per GOES) and vector magnetic fields show a re-orientation and reduction in the global α value (a measure of twist). We feel such relaxation of loop structures due to reconnections or flare could be one of the way by which field lines fall back to the photosphere to form penumbrae.
AB - We have observed formation of penumbrae on a pore in the active region NOAA10838 using Dunn Solar Telescope at NSO,Sunpot,USA. Simultaneous observations using different instruments (DLSP,UBF,Gband and CaK) provide us with vector magnetic field at photosphere, intensity images and Doppler velocity at different heights from photosphere to chromosphere. Results from our analysis of this particular data-set suggests that penumbrae are formed as a result of relaxation of magnetic field due to a flare happening at the same time. Images in Hα show the flare (C 2.9 as per GOES) and vector magnetic fields show a re-orientation and reduction in the global α value (a measure of twist). We feel such relaxation of loop structures due to reconnections or flare could be one of the way by which field lines fall back to the photosphere to form penumbrae.
UR - https://www.scopus.com/pages/publications/84883019946
UR - https://www.scopus.com/pages/publications/84883019946#tab=citedBy
U2 - 10.1017/S1743921311015420
DO - 10.1017/S1743921311015420
M3 - Conference contribution
AN - SCOPUS:84883019946
SN - 9780521760621
T3 - Proceedings of the International Astronomical Union
SP - 303
EP - 307
BT - The Physics of Sun and Star Spots
A2 - Choudhary, Debi Prasad
A2 - Strassmeier, Klaus
ER -