We present a visual determination of the number of bright points (BPs) existing in the quiet Sun, which are structures thought to trace intense kG magnetic concentrations. The measurement is based on a 0farcs1 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 3 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.
Advertised on
References
(2010) Magnetic bright points in the quiet Sun. ApJ, 715, L26
It may interest you
-
An international team of researchers led by the Instituto de Astrofísica de Canarias (IAC) and the Universidad de La Laguna (ULL), has unveiled a breakthrough explanation for the origin of tiny, jet-like plasma ejections in the solar atmosphere, known as “nanojets.” These elusive events which are recently discovered by the NASA’s solar telescopes are thought to play an important role in heating and sustaining the solar corona at temperatures above one million Kelvin. Why Study Nanojets? For decades, solar physicists have been puzzled by the so-called “coronal heating problem.” While the SunAdvertised on -
Only a handful of observations truly constrain the nature of dark matter, which is why dozens of different physical models are still viable. Several of the most popular alternatives predict that dark matter halos slowly “thermalize” over time, gradually changing shape and expanding until they form a central region of nearly constant density -- a core. This transformation would not occur if the dark matter particles were completely collision-less, as assumed in the standard model. Therefore, the presence or absence of such a core provides a powerful way to distinguish between the standardAdvertised on -
Dormant black holes in X-ray transients can be identified by the presence of broad Hα emission lines from quiescent accretion discs. Unfortunately, short-period cataclysmic variables can also produce broad Hα lines, especially when viewed at high inclinations, and are thus a major source of contamination. Here we compare the full width at half maximum (FWHM) and equivalent width (EW) of the Hα line in a sample of 20 quiescent black hole transients and 354 cataclysmic variables (305 from SDSS I to IV) with secure orbital periods (Porb) and find that: (1) FWHM and EW values decrease with PorbAdvertised on