https://www.cloudynights.com/topic/570036-advice-for-first-time-eclipse-watchers/
To view the lunar limb profiles and 'Baily's Beads Simulation', click on the map anywhere in the eclipse path. A popup will appear with a table showing the times of different points in the eclipse. On the right hand side is a column labeled 'LC'.
Click the 'LC' header (it's a link) and it'll bring up the limb profile and Baily's Bead simulation.
For instance, below is the simulation run for the Madras airport. Notice how prominent they are and are clearly defined.
Immediately below the Madras Airport simulation, is a simulation for a spot two miles north on the totality centerline, on U.S. 97.
Note the difference in appearance.
月球邊緣 lunar limb 然而，對應於月球表面的資料允許天為學家預測給定的任何時間月球剖面的確實高度 。月球邊緣的不規則是造成倍里珠的主要原因 －在日全食的時候，某些地方的陽光可以成串的通過，在別的地方卻不行。
黑色的天空對比於明亮的邊緣，使得這個現象成為測試望遠鏡和雙筒鏡的光學標的。
觀星工具 
