Flapstaff ceremony

The flapstaff ceremony in Yaxchilan was first described by Schele and Freidel (1990) as a tropical year station. Additionally, at El Cayo and Site R the same flapstaff ceremony was recorded on two other monuments. Except the associated Long count date from El Cayo, all Long count dates have about the same remainder of the tropical year when counted from the Era base date.

Site

Monument

Long Count

Tzolk’in

Haab

Remainder

Site R

 

9 14 15 14  1

 6 Imix

14 Yaxk'in

316.19

 

or

9 14 16 14  6

 7 Kimi

14 Yaxk'in

315.95

 

or

9 14 17 14 11

 8 Chuwen

14 Yaxk'in

315.71

 

or

9 15  8 17  6

 6 Kimi

14 Yaxk'in

313.05

 

or

9 15  9 17 11

 7 Chuwen

14 Yaxk'in

312.80

Yaxchilan

Stela 16

9 15  3 16  6

 6 Kimi

19 Yaxk'in

319.26

 

or

9 15  4 16 11

 7 Chuwen

19 Yaxk'in

319.01

 

or

9 15  5 16 16

 8 Kib

19 Yaxk'in

318.77

Yaxchilan

Stela 11

9 15  9 17 16

12 Kib

19 Yaxk'in

317.80

Yaxchilan

Lintel 33

9 15 16  1  6

 5 Kimi

19 Yaxk'in

316.35

Yaxchilan

Lintel 9

9 16 17  6 12

 1 Eb

 0 Mol

312.26

Yaxchilan

Lintel 50

none recorded

 

 

 

El Cayo

Panel 1

9 16  0  2 16

 6 Kib

 9 Mol

325.38

The upright standing flapstaff might shown the function as a device to observe the Sun during the zenith passage (Fuls 2000:102-3). It is necessary to control the position of the flapstaff, with the twined string functioned as a plumbline inside the hollow tube to hold the instrument vertically. The zenith passage of the Sun results in a minimal length of the midday shadow. This means, that it might be possible to determine the date of the zenith passage in a range of about ±3 days, because of the half shadow, and the daily change of the maximum altitude of the Sun.

The remainder of the tropical year should fit to the other tropical year data from Uaxactun and other monuments. The Long Count dates of the flapstaff ceremony are separated by about 46.9 and 46.5 days to the previous and the next group of tropical year stations. While these dates represent all four quarters of the tropical year, the dates of the flapstaff ceremony can not belong to a tropical year station like one of the equinoxes or the solstices.

Other specific dates of the tropical year are the first and the second zenith passage. The date of the zenith passage depends on the latitude of the observation, which is 16.89° for Yaxchilan. A zenith passage at this latitude falls 48.0 days after the spring equinox and 45.5 days after the summer solstice. Because of the similar intervals and the dispersion of the remainders (+- 3 days) the flapstaff ceremony might fall on one of two possible zenith passages.

The use of the WF(660208) correlation results in the fit to the first zenith passage after spring equinox (+-2.4 days). In the GMT (584285) correlation the data fit to the summer solstice (+-3.2 days), but this is contradicted by the other tropical year data.

Astronomical Event of the Flapstaff Ceremony: Comparing WF and GMT correlation

Monument

Long Count

WF

GMT

Stela 16

9.15.3.16.6

1st zenith passage +4

summer solstice +5


or 9.15.4.16.11

1st zenith passage +3

summer solstice +5


or 9.15.5.16.16

1st zenith passage +3

summer solstice +4

Stela 11

9.15.9.17.16

1st zenith passage +2

summer solstice +4

Lintel 33

9.15.16.1.6

1st zenith passage -1

summer solstice +2

Lintel 9

9.16.17.6.12

1st zenith passage -3

summer solstice -2