Analysis of the

PARTIAL LUNAR ECLIPSE  20080816/17

Isabella Plains Lunar Observatory Australia

Crater Timings

Predictions of crater timings were provided for this eclipse. To date only one observer has submitted data, Wolfgang Vollmann of Wien, Austria using a refractor 130/1040mm at X55.

The summary of reductions of my predictions and Wolfgang's observations are as follows (the complete list of Wolfgang's crater timing reductions are here):

ANALYSIS OF LUNAR ECLIPSE OBSERVATIONS

-  by BYRON W. SOULSBY, ISABELLA PLAINS LUNAR OBSERVATORY AUSTRALIA

****  SUMMARY  ****

 STATISTICAL ACCEPTANCE USED IS 0 < %E < 4

CRATER TIMING REDUCTIONS FOR 20080816

 IMMERSIONS                    EMERSIONS 

OBSERVER

NUMBER

MEAN %E

M E

NUMBER

MEAN %E

M E

 

 

 

 

 

 

 

IMMERSION PREDICTIONS

400

1.8705

0.0123

8

2.2902

0.0159

EMERSION PREDICTIONS

 

 

 

403

2.4280

0.0070

VOLLMANN WOLFGANG

7

1.7184

0.1374

42

2.0173

0.092

OVERALL MEAN %E FOR  407  IMMERSIONS IS  1.8678,  +/-0.014

OVERALL MEAN %E FOR  453  EMERSIONS IS  2.3875,  +/-0.0150,

 VALUES OF  F & FM ARE 298.26, 214.86

DATE: 08-24-2008 AT TIME 14:40:23

Image Analysis

Here is a nice composite image of this partial eclipse by Anthony Ayiomamitis. Using Digimizer measurement of the umbra with the semi-diameter of the Moon at 0.2557o was 0.696o.

eclipse

Here is another composite image by P. Dominguez. Again, using Digimizer measurement of the umbra with the Moon at 0.2557o was 0.697o.

lpo



Bernard Durand has again made his excellent images available for this eclipse analysis. Seven of these can be seen here.
Analysis of the images has commenced and here is one example (image taken at 21h05m01sUT):

21.05.01


Using Digimizer the above image gave an umbral semi-diameter of 0.636o with the Moon calibrated to 0.2557o, and
using ImageJ for the edges to provide good measurement data is shown below (note the stars at lower left and right):

21.05.01e.jpg

Using Digimizer the above "edges" image gave a slightly increased umbral semi-diameter of 0.697o with the Moon calibrated to 0.2557o.
The Measured Umbra

The semi-diameter of the umbra has been computed and compared with the Digimizer measurements of the calibrated umbra from still images made with my Panasonic NV-GS15 Photoshot, and those of Bernard's. The final data including the values of the crater timing reduction observed radius (ro) is here.


This image analysis is supplemented by a Mathmatica approach and compared with the computed values of Fi for this eclipse. A pdf file describing this can be seen here.

The elusive Penumbra

By enhancing "edges" of images with NIH Image (an earlier version of ImageJ) of the penumbral eclipse of 19980313 distinctive results were obtained showing clearly the penumbra at the top right in both images (the second rotated image shows the Digimizer penumbra measurement of 0.648o with the Moon calibrated at 0.2458o):

threshold.gif               thresholdd                penumbra2.gif

In an attempt to again reveal the penumbra during this partial lunar eclipse, several videos were made using my 40mm Unitron and LPI camera output fed to a MacBook.
Three image captures are shown below for this analysis:

Here the first captured frame at 18h23m (UT) from my Unitron/LPI camera and MacBook to show the penumbra for measurement:

11.jpg

Here is a second captured frame at 18h29m (UT) from my Unitron/LPI camera and MacBook to show the penumbra for measurement:

21.jpg

Here is a third captured frame at 18h38m (UT) from my Unitron/LPI camera and MacBook to show the penumbra for measurement:

31.jpg

The above images were processed and measured using Digimizer to find the observed value of the penumbra (F1) and the Umbra (F2) which were compared with the topocentric computed values Fp  and Fu from my new QuickBasic program ViaX8.exe for my temporary site at Isabella Plains North. The final results can be seen here.

Produced by the Isabella Plains Lunar Observatory Australia 20081207.