Solar Eclipse Maestro Icon

Lunar Limb Profile Window

The window displays the lunar limb profile during the eclipse from your location.

  1. Choose Display > Lunar Limb Profile…
    Eclipse Lunar Limb Profile Window Eclipse Lunar Limb Profile Contextual Menu
Eclipse contact times, magnitude and duration of totality or annularity all depend on the angular diameters and relative velocities of the Moon and Sun. The Moon exhibits an irregular limb when seen in profile, due to its surface topography. Most eclipse calculations assume some mean radius that averages high mountain peaks and low valleys along the Moon’s rugged limb. Kaguya probe and Lunar Reconnaissance Orbiter data or Watts charts are used for higher accuracy in those calculations. The radial scale of the limb profile in the figure is exaggerated so that the true limb’s departure from the mean lunar limb is readily apparent.
The mean limb with respect to the center of figure of Kaguya’s, Lunar Reconnaissance Orbiter or Watts’ data is shown as a turquoise dashed line along with the mean limb with respect to the center of mass shown as a solid red line. The position angles of second and third contacts are clearly marked with orange and green arrows (dotted for corrected contacts) along with the north pole of the Moon’s axis of rotation in blue, the north pole of the Sun’s axis of rotation in yellow and the observer’s zenith at mid-totality in mauve.

A contextual menu, that can be invoked with a right click, will let you select various options:
  • Orientation - Select the diagram orientation either from Celestial North Up, Zenith Up or Solar North Up. Celestial North Up by default.
  • Height Exaggeration Factor - Select the lunar height exaggeration from 2 to 100 times. 10 times by default.
  • Show Solar Position Outlines - Show or hide the dotted outlines of the position of the Sun at the second and third contacts. Hidden by default.
  • Show Displacement Curves - Show or hide the epicyclic curves used for computing the time offsets at the second and third contacts. Hidden by default.
  • Display Baily’s Beads at - Select the time offset, from 1 to 5 seconds, before second contact and after third contact for which you want to visualize the Baily’s beads. Hidden by default.
  • Show Corrected Contact Positions - Show or hide the corrected second and third contact positions. Displayed by default.
  • Use for Limb Corrected Contacts - Correct the second and third contact times using the lunar limb profile. On by default. When off and if a file based limb correction was provided, then a star in the main screen window will indicate that the correction has been read from the file.
  • Show Location Name and Timezone - Print or not the observer’s location name and timezone inside the PDF file. Enabled by default.
  • Save PDF File… - Lets you create a color high-resolution PDF file containing the lunar limb profile.
  • Window Transparency - The window can be made more or less opaque.