Magnetic bright points in the quiet Sun

TL;DR

This study provides a highly detailed count of bright points in the quiet Sun, revealing a higher density than previously known, and estimates their contribution to solar magnetic flux.

Contribution

First direct high-resolution measurement of bright point density in the quiet Sun, significantly increasing previous estimates and quantifying their magnetic flux contribution.

Findings

Bright points cover 0.9% to 2.2% of the solar surface.

Detected bright points contribute 13 to 33 G to magnetic flux.

Number of bright points is three times higher than previous estimates.

Abstract

We present a visual determination of the number of bright points (BPs) existing in the quiet Sun, which are structures though to trace intense kG magnetic concentrations. The measurement is based on a 0.1 arcsec angular resolution G-band movie obtained with the Swedish Solar Telescope at the solar disk center. We find 0.97 BPs/Mm^2, which is a factor three larger than any previous estimate. It corresponds to 1.2 BPs per solar granule. Depending on the details of the segmentation, the BPs cover between 0.9% and 2.2% of the solar surface. Assuming their field strength to be 1.5 kG, the detected BPs contribute to the solar magnetic flux with an unsigned flux density between 13 G and 33 G. If network and inter-network regions are counted separately, they contain 2.2 BPs/Mm^2 and 0.85 BPs/Mm^2, respectively.