Solar Limb Darkening Function from Baily's Beads Observations

TL;DR

This paper presents a high-resolution ground-based method to measure the solar diameter using Baily's Beads during eclipses, incorporating lunar limb profiles from satellite data to refine solar edge detection.

Contribution

It introduces a novel approach combining eclipse observations and lunar limb profiles to accurately determine the solar limb darkening function from the ground.

Findings

Detected solar limb light at least 0.65 arcsec beyond the inflection point.

Suggests reevaluating historical eclipse measurements made with naked eye.

Demonstrates the method with 2010 eclipse observations.

Abstract

We introduce a method to measure with high resolution the solar diameter from the ground, through the eclipse observations by reconsidering the definition of the solar edge. The outer part of the Limb Darkening Function (LDF) is recovered using the luminosity evolution of a Baily's Bead and the profile of the lunar limb available from the Kaguya satellite. The method proposed is applied for the videos of the eclipse in January, 15, 2010 recorded by Richard Nugent in Uganda and Andreas Tegtmeier in India. The result shows light from solar limb detected at least 0.65 arcsec beyond the LDF inflection point, and this fact may suggest to reconsider the evaluations of the historical eclipses made with naked eye.