PENUMBRAL-LIKE FILAMENTS IN THE SOLAR PHOTOSPHERE AS A MANIFESTATION OF FLUX EMERGENCE
- Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 78, I-95123 Catania (Italy)
- INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy)
Rare observations of the solar photosphere show the appearance of orphan penumbrae, filamentary structures very similar to a bundle of sunspot penumbral filaments not connected to any umbra. Lim et al. found an orphan penumbra in active region NOAA 11391 near a mature sunspot. We analyze a different data set to study the same structure using the Solar Optical Telescope on board the Hinode satellite. Spectropolarimetric measurements along the Fe I 630.2 nm pair, complemented by G-band and Ca II H filtergrams, show the evolution of this penumbral-like structure and reveal that an emerging flux region is its ancestor. We find new evidence for the interaction between the emerging flux and the pre-existing field that leads to a brightening observed near the base of the chromosphere. Our analysis suggests that as a result of the combination of photospheric flux emergence and magneto-convection in inclined fields the horizontal component of the emerging field can be trapped in the photosphere by the overlying fields and form a structure resembling penumbral filaments.
- OSTI ID:
- 22365856
- Journal Information:
- Astrophysical Journal Letters, Vol. 786, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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