Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2011-12-12
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
Accepted for publication in A&A. 8 pages, 6 Figs., 1 Table
Scientific paper
CONTEXT: The quiet Sun magnetic fields produce ubiquitous bright points (BPs) that cover a significant fraction of the solar surface. Their contribution to the total solar irradiance (TSI) is so-far unknown. AIMS: To measure the center-to-limb variation (CLV) of the fraction of solar surface covered by quiet Sun magnetic bright points. The fraction is referred to as 'fraction of covered surface', or FCS. METHODS: Counting of the area covered by BPs in G-band images obtained at various heliocentric angles with the 1-m Swedish Solar Telescope on La Palma. Through restoration, the images are close to the diffraction limit of the instrument (~0.1 arcsec). RESULTS: The FCS is largest at disk center (~1 %), and then drops down to become 0.2 % at 'mu'= 0.3 (with 'mu' the cosine of the heliocentric angle. The relationship has large scatter, which we evaluate comparing different subfields within our FOVs. We work out a toy-model to describe the observed CLV, which considers the BPs to be depressions in the mean solar photosphere characterized by a depth, a width, and a spread of inclinations. Although the model is poorly constrained by observations, it shows the BPs to be shallow structures (depth < width) with a large range of inclinations. We also estimate how different parts of the solar disk may contribute to TSI variations, finding that 90 % is contributed by BPs having 'mu' > 0.5, and half of it is due to BPs with 'mu' > 0.8.
Almeida Jorge Sanchez
Bonet Jose Antonio
Cabello I.
No associations
LandOfFree
Center-to-limb variation of the area covered by magnetic bright points in the quiet Sun does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Center-to-limb variation of the area covered by magnetic bright points in the quiet Sun, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Center-to-limb variation of the area covered by magnetic bright points in the quiet Sun will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-708811