| Image Comparisons with Fred Espenak's Corrected Eclipse Predictions |
| 13:11:15.8 UT Predicted Second Contact Correction +10.6 seconds (nearest image 13:11:16 UT). Baily's beads are still visible on southern edge. |
| 13:12:17.2 UT Predicted Third Contact Correction +0.7 second (nearest image 13:12:17 UT) Note that arrow indicating the third contact point is very close to the first of Baily's beads appearing 2 seconds before (see below). Large bead at 212 degrees already well formed. |
| 13:11:18 UT Observed Second Contact Last of Baily's beads appears to fade out near the 182 degree point, on the western limb (using the center of mass, solid line, scale). It is just on the east limb using the center of figure, dashed line, scale. |
| 13:12:15 UT Observed Third Contact Totality ends with appearance of first bead at about 203 degrees, very near arrow indicating predicted third contact. |
| South down, West on right. Click on images for full enlargement |
| I was intrigued by Richard Bareford's contact timings made near the southern limit of the 2001 eclipse path. He reported predicted contact timings from several sources (Bureau des Longitudes, O'Byrne, and Van Flandern) as well as his own measured timings via his digital camcorder. The results were published on his web page but I will repeat them here for convenience: Source: 2. Contact P 3. Contact P Bureau des Longitudes 13:10:53.4 160 13:12:17.2 205 O'Byrne 13:11:05.4 163 13:12:17.4 202 Van Flandern 13:11:03 NA 13:12:14.0 NA Observation 13:11:18 182 13:12:15 203 Bareford reports his coordinates as:16° 02.969 S, 28° 51.308 E, 1300 ft (or 400 m). Using this position, I decided to calculate contact timings using the Watt's lunar limb profile to correct the times. The results are as follows: Source: 2. Contact P 3. Contact P Observation (Bareford) 13:11:18 182 13:12:15 203 Espenak (mean limb) 13:11:05.1 163 13:12:16.5 202 Espenak (limb correct) 13:11:15.8 NA 13:12:17.2 NA A limb profile diagram with detailed predictions for Bareford's position is posted at: http://sunearth.gsfc.nasa.gov/eclipse/TSE2001/TSE2001fig/TSE2001Bareford.gif As you can see from the above table, the limb profile introduces corrections of +10.6 sec and +0.7 sec, respectively to the mean limb (and center of mass) predictions. Bareford quotes the observed contact times only to the nearest whole second. Still, I was pleased to see agreement to within 2 seconds between observation and prediction at a locaton so close to the southern limit. Nevertheless, the differences point out the need for an improved lunar limb data base. This type of work is being carried out by David Dunham and IOTA (International Occultation Timing Association) to refine sizes and positions of features along the Moon's limb. Eclipse chasers and amateurs can make an important contribution by participating in IOTA eclipse observations near the limits: http://www.occultations.org/ - Fred Espenak [from his Solar Eclipse Mailing List posting of 6 August 2001] |
 |
 |
 |
 |