What are solar faculae?

1Kostyk, RI
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2013, 29(1):50-57
Start Page: Solar Physics
Language: Russian

We present some results of observations of a facula area located near the solar disc center. The observations were performed at the German Vacuum Tower Telescope of the Observatorio del Teide (Tenerife) with the simultaneous use of two instruments: TESOS in the Ba II λ 455.4 nm line to measure intensity variations along the photosphere and TIP in the Fe I (λλ1564.3—1565.8 nm) line to measure Stokes parameters. Using the Fourier filtering procedure, we separated the convective and oscillatory components of intencity field. The Stokes parameters of the Fe I λ 1564.8 nm and λ 1565.2 nm lines were inverted using SIR inversion code to estimate the magnetic field intencity. We found that continuum facular contrast of intergranular lines was nearly constant as a function of magnetic field intencity (from 300 to 1600 gauss). This result casts some suspicion on the assertion that solar faculae are an accumulation of small magnetic flux tubes, but rather indicates that hot granular walls are seen due to some decrease of the matter transparency in the presence of strong (about 1 kgauss) magnetig field.

Keywords: magnetic field, solar faculae, Sun

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