2007/02/28 by S. Vargas Dominguez, S. Vargas Domínguez, J. A. Bonet +7 · 4 citations
Computer Science · Physics and Astronomy · #Adaptive optics and wavefront sensing #Solar Radiation and Photovoltaics #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.1086/518123
4 pages, 4 figures, To appear in ApJ Letters
arxiv created 2007/03/01 · openalex publication_date 2007/04/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Proper motions in a sunspot group with a δ-configuration and close to the solar disk center have been studied by employing local correlation tracking techniques. The analysis is based on a more than 1 hr time series of G-band images. Radial outflows with a mean speed of 0.67 km s -1 have been detected around the spots, the well-known sunspots moats. However, these outflows are not found in those umbral core sides without penumbra. Moreover, moat flows are only found in those sides of penumbrae located in the direction marked by the penumbral filaments. Penumbral sides perpendicular to them show no moat flow. These results strongly suggest a relation between the moat flow and the well-known, filament-aligned Evershed flow. The standard picture of a moat flow originating from a blocking of the upward propagation of heat is discussed in some detail.