The frequency of non-central eclipses

Updated: 28 June 2008

During a non-central eclipse the centre line of the moon's shadow does not touch the surface of the earth. The graph below shows the distribution of non-central eclipses (in blue) during from -1999 until 3000. A least square fit gave a period of 5.9 centuries Again this seems to be the same period that governs many other distributions (e.g. lunar tetrads, total penumbral eclipses, duos, double duos, and off course the frequency of solar eclipses in general).

Comparing the distribution of non-central eclipse with the distribution of eclipses that are part of a double-duo (4 eclipses in a 7 lunation period) shows that non-central eclipses occur mainly in periods with no or few eclipses  that are part of a double duos series. (Note the different scales on the y-axis)


The table below lists the non-central eclipses. For subsequent non-central eclipses in the same Saros series, the eclipse has to occur near the perihelion passage. These are always non-central annular events. Some Saros series (27, 64, 103) have 3 subsequent non-central eclipses. Saros 153 will even have 4 subsequent non-central annular eclipses (17 Dec 2104, 28 Dec 2122, 8 Jan 2141 and 19 Jan 2159). The following 2 eclipses in this Saros will also have no northern limit, but will be central. (see Morsels IV, ch. 12)

 
Date Saros Type Gamma
-1954 Jan 28 19 A+ 1.0192
-1859 May 25 -2 T+ 1.0015
-1784 Jun 5 28 A- -1.0116
-1718 Apr 27 1 T- -0.9988
-1660 Mar 17 3 A- -1.0038
-1555 Jan 26 6 A+ 1.012
-1502 Apr 9 34 A- -1.008
-1462 Feb 17 36 T- -0.9981
-1461 Jan 8 8 A+ 0.9994
-1455 Sep 24 40 A- -0.9989
-1423 Dec 27 38 A- -1.0132
-1404 Jan 7 38 A- -0.9974
-1339 Jul 4 44 A- -1.0061
-1038 Apr 9 22 T+ 1.0023
-1020 Oct 14 27 A- -1.005
-1002 Oct 25 27 A- -1.0163
-984 Nov 4 27 A- -1.0234
-915 Feb 28 25 T- -1.0012
-909 Nov 15 57 T+ 0.9976
-905 Mar 10 54 T- -1.0053
-869 Sep 25 59 A+ 1.0040
-839 Jul 26 32 T+ 1.0095
-829 Aug 5 61 T+ 0.9972
-822 Mar 23 55 A+ 1.0009
-641 Jun 28 65 A+ 0.9992
-500 May 29 68 A- -0.9975
-470 Sep 23 46 A+ 1.0061
-405 Apr 1 42 A+ 1.0107
-300 Feb 11 45 A- -1.0021
-290 Aug 15 79 T+ 1.0017
-243 Dec 31 47 T- -0.9993
-207 Aug 27 80 A- -1.0082
-159 Jul 8 53 T- -1.0096
-149 Jan 22 77 A+ 1.0200
-101 May 29 55 A- -1.0032
-26 Jun 8 85 T+ 1.0068
40 Apr 30 58 A+ 1.0100
115 May 11 88 T- -1.0051
152 Apr 22 60 A+ 0.9989
195 Dec 19 64 A+ 0.9991
213 Dec 29 64 A+ 1.0047
232 Jan 10 64 A+ 1.0141
235 Oct 29 66 A+ 1.0029
274 Oct 17 96 A- -1.0113
332 Mar 13 93 A+ 1.0036
350 Sep 18 98 A- -1.0119
351 Feb 12 65 T- -1.0018
444 Mar 5 95 A+ 1.0045
596 Jul 1 104 A- -0.9988
625 Jun 10 105 A+ 1.0042
720 Apr 12 79 A- -1.0037
767 Sep 27 85 A- -1.0165
825 Feb 21 82 A+ 1.0002
861 Sep 8 87 T- -1.0032
872 Aug 8 88 A+ 1.0114
890 Feb 23 83 T- -1.0005
976 Feb 3 114 A- -1.0182
994 Aug 9 119 T+ 0.9985
1277 May 4 97 A- -1.0071
1378 Nov 20 103 A- -0.9981
1396 Dec 1 103 A- -1.0074
1400 Mar 26 100 A+ 1.0058
1414 Dec 12 103 A- -1.0145
1418 Sep 30 105 T- -1.0021
1429 Aug 30 106 A+ 0.9988
1435 Nov 20 133 A+ 0.9991
1511 Oct 21 135 A+ 1.0058
1569 Mar 17 132 A- -1.0033
1598 Aug 31 138 A- -1.0126
1656 Jul 21 140 T- -0.9983
1928 May 19 117 T- -1.0048
1950 Mar 18 119 A- -0.9988
1957 Apr 30 118 A+ 0.9992
1957 Oct 23 123 T- -1.0022
1967 Nov 2 152 T- -1.0007
2014 Apr 29 148 A- -1.0000
2043 Apr 9 149 T+ 1.0031
2043 Oct 3 154 A- -1.0102
2104 Dec 17 153 A+ 1.0120
2122 Dec 28 153 A+ 1.0072
2126 Apr 22 150 A- -1.0051
2141 Jan 8 153 A+ 1.0024
2159 Jan 19 153 A+ 0.9974
2459 Jun 1 164 T- -1.0097
2467 Nov 27 140 A+ 1.0051
2485 Dec 7 140 A+ 1.0242
2507 Apr 13 137 A- -1.0006
2542 Dec 8 170 T- -0.9975
2618 Nov 9 172 A- -1.0033
2644 Jan 2 171 A+ 1.0021
2662 Jan 12 171 A+ 0.9996
2846 Aug 13 178 A- -1.0057
2941 Jun 16 152 A+ 1.0004
2999 Oct 30 159 A- -1.0023

"T+" = Non-central total eclipse with no northern limit
"T-" = Non-central total eclipse with no southern limit
"A+" = Non-central annular eclipse with no northern limit
"A-" = Non-central annular eclipse with no southern limit

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