Magnetic topology of a naked sunspot: Is it really naked?

Abstract

The high spatial, temporal and spectral resolution achieved by Hinode instruments give much better understanding of the behavior of some elusive solar features, such as pores and naked sunspots. Their fast evolution and, in some cases, their small sizes have made their study difficult. The moving magnetic features, despite being more dynamic structures, have been studied during the last 40 years. They have been always associated with sunspots, especially with the penumbra. However, a recent observation of a naked sunspot (one with no penumbra) has shown MMF activity. The authors of this reported observation expressed their reservations about the explanation given to the bipolar MMF activity as an extension of the penumbral filaments into the moat. How can this type of MMFs exist when a penumbra does not? In this paper, we study the full magnetic and (horizontal) velocity topology of the same naked sunspot, showing how the existence of a magnetic field topology similar to that observed in sunspots can explain these MMFs, even when the intensity map of the naked sunspot does not show a penumbra.

6 pages, 2 figures

References in corpus (6)

• The Solar Optical Telescope for the Hinode Mission: An Overview
• Detection of sea-serpent field lines in sunspot penumbrae
• Flow Field Evolution of a Decaying Sunspot
• Spectropolarimetry of a decaying sunspot penumbra
• Moat flow in the vicinity of sunspots for various penumbral configurations
• On the Moat-Penumbra Relation

Cited by in corpus (4)

• Plasma flows and magnetic field interplay during the formation of a pore
• Evolution of the flow field in decaying active regions II. Converging flows at the periphery of naked spots
• Exploring magnetic field properties at the boundary of solar pores: A comparative study based on SDO-HMI observations
• Decay of a photospheric transient filament at the boundary of a pore and the chromospheric response