Small-scale bright point characteristics at high-resolution with the Daniel K. Inouye Solar Telescope

TL;DR

This study utilizes the high-resolution capabilities of DKIST to analyze small-scale bright points on the Sun, revealing their lifetimes, velocities, and area distributions, and examining the effects of spatial resolution and seeing conditions.

Contribution

First high-resolution analysis of solar bright points with DKIST, highlighting differences in area distribution and the impact of observational resolution and seeing effects.

Findings

Bright points have an average lifetime of 95 seconds.

The area distribution peaks at 2300 km², lower than previous studies.

Seeing effects influence the measured properties of bright points.

Abstract

Bright points (BPs) are small-scale, dynamic features that are ubiquitous across the solar disc and are often associated with the underlying magnetic field. Using broadband photospheric images obtained with the Visible Broadband Imager at the National Science Foundation's Daniel K. Inouye Solar Telescope (DKIST), the properties of BPs have been analyzed with DKIST for the first time at the highest spatial resolutions achievable. BPs were observed to have an average lifetime of 95$\pm$29 s and a mean transverse velocity of 1.60$\pm$0.41 km/s. The BPs had a log-normal area distribution with a peak at 2300 km$^2$. Transverse velocity and lifetimes across the DKIST images were comparable and consistent with previous studies. The area distribution of the DKIST data peaked in areas significantly lower than those from the literature. This was explored further and was observed to be due to an overestimation of BP areas due to the merging of close features when the spatial resolution is reduced, in tandem with possible over-splitting of features in the DKIST images. Furthermore, the effect of variable seeing within the data was determined. This showed that the average spatial resolution of the data was around 0.''034$\pm$0.''007 in comparison to the theoretical diffraction-limit of 0.''022. Accounting for the influence of seeing, the peak of the area distribution of BPs in the DKIST data was estimated as 4800 km$^2$, which is still significantly lower than previously observed.