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Sundial, calendar and Khmer temples
Astro-archaeology = Astroarchaeology
Sunrises
and sunsets at Prasat Phanom Rung in
UNESCO's International Year of Astronomy, 2009าพระวิหาร |
Nandin fronting Shiva, the lingam,
and the setting sun
INTRODUCTION
The astronomical aspects of Prasat Phanom Rung are:
• 1. Solar: The illumination of the linga occurring close to 14
days before and after the two equinox days. Annually there are 4 solar
events. At each event the sun will be visible the day before and after
as well. On each day the sun will be visible for some 8 minutes.
• 2. Solar-lunar: The period from the solar event before equinox
to the event after equinox is close to one synodic month. The moon will
be located at the same location (zodiacal sign, naksatra) at both
events.
• 3. Eclipses: When a solar or lunar eclipse occurs at a solar
event it will most likely be repeated with some interval at a coming
solar event. The most common interval is 6 synodic months (app. 164
days).
(Ref.:
Solar-lunar events at Prasat Phanom Rung in Spring 2007 AD.
Muang Boran Journal, May 2005, Asger Mollerup).
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1. Solar events (sunrises and sunsets)
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Sunsets
in
March 2009 |
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Fig 1: Observed from centre line,
mid-door, 7 m outside the eastern door.
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Fig 2: Observed from centre line,
threshold, 7 m
outside the eastern door.
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5th of March: Sunset at 18:17:04
6th of March: Sunset at 18:17:14
7th of March: Sunset at 18:18:24
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Above: 5th of March 2009 |
Above: 6th of March 2009 |
Above: 7th of March 2009 |
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Sunrises
in
April 2009
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Fig 3: Observed from centre line,
mid-door, 7.5 m
outside the western door.
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Fig 4: Observed from centre line,
threshold, 7.5 m
outside the western door.
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2nd of
April: Sunrise at 06:03:24
3rd of April: Sunrise at 06:02:42
4th of April: Sunrise at 06:02:01
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Sunrises
in
September 2009 |
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Fig 5: Observed from centre line,
mid-door, 7.5 m
outside the western door.
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Fig 6: Observed from centre line,
threshold, 7.5 m
outside the western door.
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8th of
September: Sunrise at 05:56:37
9th of September: Sunrise at 05:56:40
10th of September: Sunrise at 05:56:43
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Sunsets
in
October 2009 |
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Fig 7: Observed from centre line,
mid-door, 7 m outside the eastern door.
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Fig 8: Observed from centre line,
threshold, 7 m
outside the eastern door.
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5th of October: Sunset at 17:55:02
6th of October: Sunset at 17:54:20
7th of October: Sunset at 17:53:39
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Bold text marks the days when the sun rises or sets the
closest to the centre of the 15-doorways.
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2. Solar-lunar events: Naksatra
(lunar houses)
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| Fig. 9:
A few hours after sunset 6th March 2009 the moon will be
located in the zodiacal sign Gemini, the Twins. |
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Fig. 10: A
few hours before sunrise 3rd April 2009 the moon will
have returned to the same location between the Twins. |
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The moon changes position every night when compared
with the stars. After one (synodic) lunar month the moon
will have passed all 12 zodiacal signs and have returned
to its starting point - as illustrated above.
The celestial sphere can be divided into 12 solar
houses, the zodiacal signs - or into 27 lunar houses,
the naksastras.
The ancient Khmers would for calendric and astrological
reasons have paid more attention to the moons
naksastra location, which is in Punarvasu.
The Khmer
calendar is based on the Indian manual on astronomy, the
Surya Siddhanta, as evidenced by dated Khmer
inscriptions.
The Surya Siddhanta has been computerized by professor
Yano (Pancanga)
according to which the solar-lunar events at Prasat
Phanom Rung in 2009 will fall on the following two
dates:
1. Friday the 6th of March (Saka 1930), solar house:
Phalguna, lunar house: Punarvasu, 10th waxing day.
2. Friday the 3rd of April (Saka 1931), solar house:
Caitra, lunar house: Punarvasu, 8th waxing day.
Note that the two dates above
fall in respectively Saka 1930 and Saka 1931: The Khmer
calendric year will in 2009 start at new moon Friday the
27th of March = 1st day of Caitra, Saka 1931. |
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3. Solar and lunar eclipses
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There will be one partial solar
eclipse in the late afternoon the 26th of January 2009
followed by a second partial solar eclipse six lunar
month (or draconic months) later on the 22nd of July.
There will be no eclipses around any of the
solar-lunar events at Prasat Phanom Rung.
Rahu and Ketu (right) will so to speak be absent in 2009...
Fig. 11: Rahu and Ketu.
Rahu seizing the moon. |
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4. Other celestial events
around the sunrise on 3rd April 2009
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At dawn
three
planets will be visible on the eastern sky: Jupiter,
Mars and Venus. Jupiter will rise at 03:05, Mars at
04:33, and Venus in the early twilight at 05:13 (app. 50
minutes before sunrise)
Indra is associated with the planet Jupiter
and he is also the leader of the
guardians of the cardinal directions, the dikpala, and
depicted towards the rising sun on many Khmer temples.
Indra rides on his elephant, Airavata, carrying the
thunderbolt, the vajra, in his right hand (right,
Prasat Phanom Rung).
It will be first quarter (half-moon) the 2nd of April
and thereby a holy-day in the local Buddhist lunar-solar calendar. |
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| Above: 5th of March 2009 |
Above: 6th of March 2009 |
Above: 7th of March 2009 |
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| Above: 6th of March 2009 |
Above: 6th of March 2009 |
Above: 6th of March 2009 |
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| Above: 6th of March 2009 |
Above: 6th of March 2009 |
Above: 6th of March 2009 |
Z
Latest NEWS (12 March 2009):
Year 2009 has by
UNESCO been declared the International Year of Astronomy
and 2 locations in Thailand are being considered as candidates
for Astronomical Landmarks of Thailand.: Prasat Phanom
Rung in Buriram province and the Saint Paulo Observatory in
Lopburi province.
The 7th of March
2009 the first seminar in Thailand on astro-archaeology was held
at Prasat Phanom Rung with participants from Rajabhat Buriram
and Surin, UNESCO's representatives from Chiang Mai University,
local governmental representatives from Buriram.
Speakers: Assoc. Prof. Boonrucksar Soonthornthum from Chiang Mai
University and Asger Mollerup.
Related links (in Thai):
Announcement of the International Year of Astronomy from
Science and
Technology
The official announcement about the solar events at Prasat
Phanom Rung 2009 from
News Data Center (NDT)
INDEX |
Mukdahan, March 2009
Photos, calculations and drawings
© Asger Mollerup
(Independent consultant on astro-archaeology and surveyor on Khmer
temples at Buriram Provincial Office)
macsida@thai-isan-lao.com
www.thai-isan-lao.com |