High-resolution imaging and near-infrared spectroscopy of penumbral decay

0495890 - ASÚ 2019 RIV FR eng J - Journal Article
Verma, M. - Denker, C. - Balthasar, H. - Kuckein, C. - Rezaei, R. - Sobotka, Michal - Deng, N. - Wang, H. - Tritschler, A. - Collados Vera, M. - Diercke, A. - Manrique, S. J. G.
High-resolution imaging and near-infrared spectroscopy of penumbral decay.
Astronomy & Astrophysics. Roč. 614, June (2018), č. článku A2. ISSN 0004-6361. E-ISSN 1432-0746
Institutional support: RVO:67985815
Keywords : moving magnetic features * dynamics-observatory sdo * solar optical telescope
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.209, year: 2018

Combining high-resolution spectropolarimetric and imaging data is key to understanding the decay process of sunspots as it allows us to scrutinize the velocity and magnetic fields of sunspots and their surroundings. At the time of the GREGOR observations, the leading sunspot had two light bridges indicating the onset of its decay. One of the light bridges disappeared, and an elongated, dark umbral core at its edge appeared in a decaying penumbral sector facing the newly emerging flux. The flow and magnetic field properties of this penumbral sector exhibited weak Evershed flow, moat flow, and horizontal magnetic field. The penumbral gap adjacent to the elongated umbral core and the penumbra in that penumbral sector displayed LOS velocities similar to granulation. The separating polarities of a new flux system interacted with the leading and central part of the already established active region. As a consequence, the leading spot rotated 55 degrees clockwise over 12 h.
Permanent Link: http://hdl.handle.net/11104/0288764