This orbital period is called the anomalistic month, and together with the synodic month causes the so-called " full moon cycle " of about 14 lunations in the timings and appearances of full ( and new ) Moons.
12.
As a consequence, the apparent diameter of a full moon varies, depending on when it occurs in the anomalistic month : larger near the Earth ( near perigee ); or smaller when more distant ( near apogee ).
13.
He argued that Naburimannu developed the Babylonian System A of calculating solar system ephemerides, and that later Kidinnu developed the Babylonian System B . A Greco-Roman tradition, mentioned above, attributes to Kidinnu the discovery that 251 synodic months equals 269 anomalistic months.
14.
Every third tzolkinex comes close to an even number of anomalistic months, but occurs during a different season, and in the opposite hemisphere, thus they may be of the same type ( annular vs . total ) but otherwise do not have a similar character.
15.
The number of " anomalistic months " in a tritos ( 144.68 ), having a fraction near, means every third eclipse is in nearly the same position in the elliptical orbit, so eclipses will have similar timing and total versus annular quality.
16.
Its significance is that when you start with a full moon at the perigee-which appears large, then subsequent full moons will occur ever later after the passage of the perigee; after 1 full moon cycle, the accumulated difference between the number of completed anomalistic months and the number of completed synodic months is exactly 1, and the full moon occurs again at perigee, giving a large apparent moon.
17.
Hipparchus initially used ( " Almagest " 6.9 ) his 141 B . C . E . eclipse with a Babylonian eclipse of 720 B . C . E . to find the less accurate ratio 7160 synodic months = 7770 draconitic months, simplified by him to 716 = 777 through division by 10 . ( He similarly found from the 345-year cycle the ratio 4267 synodic months = 4573 anomalistic months and divided by 17 to obtain the standard ratio 251 synodic months = 269 anomalistic months . ) If he sought a longer time base for this draconitic investigation he could use his same 141 B . C . E . eclipse with a moonrise 1245 B . C . E . eclipse from Babylon, an interval of 13645 synodic months = 148807 1 / 2 draconitic months H " 14623 1 / 2 anomalistic months.
18.
Hipparchus initially used ( " Almagest " 6.9 ) his 141 B . C . E . eclipse with a Babylonian eclipse of 720 B . C . E . to find the less accurate ratio 7160 synodic months = 7770 draconitic months, simplified by him to 716 = 777 through division by 10 . ( He similarly found from the 345-year cycle the ratio 4267 synodic months = 4573 anomalistic months and divided by 17 to obtain the standard ratio 251 synodic months = 269 anomalistic months . ) If he sought a longer time base for this draconitic investigation he could use his same 141 B . C . E . eclipse with a moonrise 1245 B . C . E . eclipse from Babylon, an interval of 13645 synodic months = 148807 1 / 2 draconitic months H " 14623 1 / 2 anomalistic months.
19.
Hipparchus initially used ( " Almagest " 6.9 ) his 141 B . C . E . eclipse with a Babylonian eclipse of 720 B . C . E . to find the less accurate ratio 7160 synodic months = 7770 draconitic months, simplified by him to 716 = 777 through division by 10 . ( He similarly found from the 345-year cycle the ratio 4267 synodic months = 4573 anomalistic months and divided by 17 to obtain the standard ratio 251 synodic months = 269 anomalistic months . ) If he sought a longer time base for this draconitic investigation he could use his same 141 B . C . E . eclipse with a moonrise 1245 B . C . E . eclipse from Babylon, an interval of 13645 synodic months = 148807 1 / 2 draconitic months H " 14623 1 / 2 anomalistic months.
