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Local Circumstances of a Solar Eclipse

version 1.0.0.0 (23.3 KB) by Meysam Mahooti
Computation of possibility of observing solar eclipse at the observer's location

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Updated 15 Jan 2018

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Although the track of the central line for a solar eclipse is often known and published years in advance, yearbooks generally contain no details of the local circumstances of an eclipse for a specific observing site. The EclTimer.m (as an extension to the Eclipse.m) enables the local circumstances of an eclipse to be calculated for any given point. The geometrical requirement for observing first or fourth contact at solar eclipses is that the observer shall be located somewhere on the curved boundary of the Moon’s penumbra. Second and third contact, in contrast, occur when the observer is at the boundary of the umbral shadow.
The EclTimer.m receives date of new Moon (year, month, day, hour), geographical longitude and latitude of the observer in [rad], then returns possibility of observing solar eclipse at the observer's location.
Time of new Moon and solar eclipse can be computed using "Phases.m" and "Eclipse.m" from the following links:
http://www.mathworks.com/matlabcentral/fileexchange/55270-moon-phases
http://www.mathworks.com/matlabcentral/fileexchange/55279-solar-eclipse
References:
Montenbruck O., Pfleger T.; Astronomy on the Personal Computer; Springer Verlag, Heidelberg; 4th edition (2000).
Meeus J.; Astronomical Algorithms; Willmann-Bell; Richmond, Virginia; 2nd edition (1998).
https://eclipse.gsfc.nasa.gov/LEcat5/deltatpoly.html

Comments and Ratings (7)

BlueEyes

Better to amend ET_UT for years >= 2005 according to http://stjarnhimlen.se/comp/time.html as follows:
---------
else
switch year
case 2005
ET_UT = 64.8;
case 2006
ET_UT = 65.0;
case 2007
ET_UT = 65.3;
case 2008
ET_UT = 65.6;
case 2009
ET_UT = 66.0;
case 2010
ET_UT = 66.2;
case 2011
ET_UT = 66.5;
case 2012
ET_UT = 66.8;
case 2013
ET_UT = 67.1;
case 2014
ET_UT = 67.5;
case 2015
ET_UT = 67.9;
case 2016
ET_UT = 68.4;
case 2017
ET_UT = 68.8;
case 2018
ET_UT = 69.2;
otherwise
ET_UT = 71.0;
---------

BlueEyes

Mismatch reference made to file EclTimer.m, frprintf() instead of fprintf()
------------
case 4
frprintf(' Total eclipse with M=');
frprintf('%5.3f', Mag);
frprintf('.\n');
------------

BlueEyes

Please, be minded about this pernicious typesetting mismatch:
frprintf() instead of fprintf(), as shown below:
------------
case 4
frprintf(' Total eclipse with M=');
frprintf('%5.3f', Mag);
frprintf('.\n');
------------
Cheers

Demi Moore

Updates

1.0.0.0

ETminUT.m and EclTimer.m are revised.

1.0.0.0

Pegasus.m is modified.

1.0.0.0

Description is updated.

1.0.0.0

The image is added.

MATLAB Release Compatibility
Created with R2017b
Compatible with any release
Platform Compatibility
Windows macOS Linux