DOI: 10.16943/ijhs/2018/v53i3/49463
Indian Journal of History of Science, 53.3 (2018) 317-324
Historical Note
The Origin of the 28 Nakatras in Early Indian
Astronomy and Astrology
Howard D Jones*
(Received 10 April 2018)
Abstract
The reason for the selection of the original lists of 28 nakatras or lunar mansions for the lunar
zodiac of ancient India and China has remained an unexplained mystery for more than 2,000 years. This
paper sets out to explain when and why these 28 divisions of the lunar zodiac were initially selected and
show how they were linked to the Indian and Chinese Bronze Age calendars and the Vedic year of 360
days.
It has been almost universally presumed by modern astronomers and assyriologists that this
early 360 day year or calendar adopted by the ancient cultures from Egypt and Mesopotamia to the Orient
was merely used as a schematic guide for calculations and astrological predictions but with little impact
on more general day to day life and with no proper link to the correct movements in the ancient skies of
the sun or moon or stars.
However this study of early Vedic Indian astronomical systems will show that the development
of their unique set of nakatras, tithis, and other systems for keeping track of the moment of Moonrise
were all founded on and related to an acceptance that the Vedic calendar of 12 months of exactly 30 days
did reflect a virtual or true astronomical reality. Once it is understood that their astronomical developments
were based directly on a 360 day year it can be seen that their systems were both accurate and precise.
Please note that references made to monthly and daily movements of the Moon will relate only to average
movements, and not to exact daily movements which are quite variable.
Key words: Amenhotep I, Assyria, Babylon, Bronze Age, Chinese lunar mansions, Coral growth
rings, Enuma Elis, Indian astronomy, Jupiter cycle, Mul Apin, Muhūrta, Nakatra, Sidereal month, Tithi,
Eruption of Thera, 360 day year, Ur III, Vedic calendar.
1. INTRODUCTION
The study is based on a range of texts
referring to the 360 day calendar and early
astronomical developments. W. St Chad
Boscawen’s ‘The Bible and the Monuments...’
discusses early Mesopotamian literature including
an account of the Deluge from the Epic of
Gilgames and descriptions of the astronomical
calendar from the Enuma Elis. Rev John Jackson
is a good source of pre Roman Latin traditions
concerning the chaotic state of the lunar calendars
before the reforms of King Numa.
‘Issues in Vedic Astronomy and Astrology’
ed. Pandya, Dikshit and Kansara, covers many
different aspects of the early Indian astronomy,
while the work by Peng Yoke Ho looks at Lunar
Mansions from a Chinese perspective. Japan,
Korea, Tibet, Mongolia, and Arabia all have
associated astronomical and astrological traditions
of a lunar zodiac and of lunar mansions. The 360
*Church Farm, Priston, Bath, Somerset, U.K., BA2 9EF, Email: sloeeyes00@gmail.com
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INDIAN JOURNAL OF HISTORY OF SCIENCE
day year has been widely discussed in relation to
early Hebrew and Christian traditions. Mayan and
other South American cultures had a very rich
selection of ancient calendars. Their use of a 360
day year was noted by William Whiston in his
work from 1696. It is unlikely that ancient Indian
and Babylonian astronomical themes and their
own 360 day year could have spread to the New
World by diffusion.
2. NAKATRAS
‘The Sun and Moon were shut in Darkness
and the 28 nakatras were fixed.’
Song of the Snow Ranges, Milarepa, (trans)
The true nature of the 360 day calendar of
the ancient World has been a matter of dispute for
centuries but irrespective of the role they played
in astronomy there must have been a date and a
year when they were first introduced. These
calendars were very precise with a solar year of
360 days composed of exactly 12 months of 30
days. Calendars of this design appeared in the
records and traditions of more than a dozen ancient
civilisations. Assyriologists and modern
astronomers argue they represented some sort of
schematic device, with the 30 day months
providing only a rough approximation for the true
lunar cycles. They always prefix the 360 day year
with terms such as ideal or model with the
implication that such ancient calendars in no way
reflected real astronomical observations of the
movements of the Sun and the Moon.
The widespread occurrence of records of
a 360 day year together with links with the story
of the Biblical Deluge, encouraged William
Whiston in 1696 to argue that a real 360 day year
had existed before the Flood. Since then Christian
and Hebrew scholars and certain Catastrophists
such as Immanuel Velikovsky, J G Radolf, and
Donald Patten have looked for evidence that could
establish the reality of the 360 day year, hoping to
find evidence of catastrophic past events to
validate stories from the scriptures or for
catastrophic myths recorded by Seneca and other
classical authors.
Some of the richest sources for the 360
day calendar are the Indian gveda texts and the
Mul Apin and Enuma Elis traditions of ancient
Assyria. Mesopotamian records were more
concerned with the solar zodiacal divisions, while
Indian astronomers and astrologers divided their
zodiac into lunar mansions or nakatras. These
roughly daily divisions of the lunar zodiac
originally became an important element of ancient
astrology and remain a key feature of Oriental
astrology to this day. But whereas many Indian
astrologers have adopted a list of 27 mansions,
Chinese astrologers remained loyal to an older list
of 28 lunar stations known as Hsiu, or Xiu. The
stations of the Moon were of limited interest to
the Greeks, Egyptians and the Babylonians but
they did represent a special feature of Arabian
astronomy. There they were named Manazils
(Manzil sing.) and it was the older complete set
of 28 mansions that Arabian astronomers searched
for amongst the stars of the night skies of the
Arabian Desert.
Today it is widely accepted that the later
list of 27 nakatras had been derived from the
number of days it takes the Moon to complete a
360 degree orbit of the Earth. This is known as
the Moon’s sidereal orbit and it takes on average
27.27 days (this interval should not to be confused
with the longer 29.5 day of the full synodic month).
But this leaves unanswered the question of why
initially lists of 28 mansions were adopted. Their
purpose, and the reason why there had originally
been the extra 28th Indian nakatras named Abhījit
appeared to have been lost in the mists of time,
but the key to understanding the need for this
additional Abhījit has always remained concealed
but hidden near by but tangled up within the
tradition
In modern times with our 365 day year the
Moon travels on average 13.2 degrees in a single
day, and it takes close to 360 ÷ 13.2 = 27.27 days
HISTORICAL NOTE: THE ORIGIN OF THE 28 NAKS. ATRAS IN EARLY INDIAN ASTRONOMY
to complete a 360 degree sidereal cycle. As already
noted this number is widely accepted as the
number which is rounded down to produce the
shorter list of 27 nakatras. But in Vedic times
the 365 day solar year wasn’t recognised and
wasn’t used. They exclusively used the 360 day
calendar with a year composed of exactly 12
months of 30 days. For a Vedic year we must
change the calculation to establish a different
sidereal period.
We know that for the Vedic year the Moon
would have moved 13 degrees in a day so to
calculate the time required for the Vedic lunar
sidereal period we just need:
360 ÷ 13 = 27.69 days
This is why 28 lunar mansions were
adopted in India and China and the other regions
that numbered their lunar mansions at the time
when they had a year of exactly 12 x 30 days.
Later when the 365 day solar year was introduced
some Indian astrologers switched to the shorter
lists of 27 nakatras, but in China and
neighbouring regions the original list of 28
mansions was retained. These two different lists
of lunar mansions still remain of fundamental
importance in Oriental astrology.
3. THE ORIGIN OF THE 12 DEGREE
DEFINITION OF THE TITHI
At the same time that the new list of 27
nakatras was introduced the alternative lunar
division known as a tithi was revised. These
divisions had previously represented 1/30th of a
lunar month. Today the tithi is said to have no
logical link to sensible celestial rhythms but its
role as a measure of Vedic time could not have
been clearer. As 1/30th of a Vedic month a single
tithi equalled one whole day or a period of 30
muhūrtas. Even though its lost some of its
significance with the change to a 365 day calendar
Indian astronomers and astrologers decided to
retain this 1/30th division of the synodic month.
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Today a technical definition for a tithi is
that it is the time taken for the Moon to separate
or move 12 degrees in relation to the position of
the Sun. With the Vedic year there would have
been a 390 degree lunar orbit each synodic month
with the Moon on average traveling 13 degrees
each day. Meanwhile in this 360 day year the Sun
must move just one degree each day. This meant
that in Vedic times the Moon would on average
move exactly 12 degrees away from Sun for every
24 hour interval or 12 degrees for each Vedic day
of 30 muhūrtas. So the current ‘12 degrees of
separation’ definition for a modern tithi matches
the precise 12 degree definition for a tithi in Vedic
times. Needham noted a similar tradition in ancient
Chinese astronomy which noted that the Moon
moved 13 degrees in a single day, while the Sun
moved just one degree.
4. THE VEDIC ORIGIN OF THE INDIAN
SYSTEM USED FOR NAMING THE MONTHS
Assyrian scholars like to claim that the
Babylonian 360 day year was just a schematic aid
for bureaucrats although unrecognised in the wider
Mesopotamian society. But developments in
Indian astronomy demonstrate that the 360 day
year and calendar was not only widely accepted it
was also used to provide names for the Indian
months. In many regions the months are named
after the central nakatras, or mansion, occupied
by the month’s Full Moon. P V Vartak (p.126)
notes in ‘Issues in Vedic Astronomy and Astrology
…’.
They named the lunar months after the nakatras
in the vicinity of which the full moon shone.
This is how the Indian Months got their
names. But this system can only work for a
calendar in which the twelve 30 day lunar months
are synchronised exactly with the 360 days of the
solar year. With synchronised months this system
would work perfectly. With our modern year of
365 days this month naming system makes no
sense. It is difficult to understand how this method
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could ever have been applied unless the Vedic
calendar was somehow based on real astronomical
observations.
If we check Assyrian and Babylonian texts
aspects of their lunar cycles match Vedic patterns.
In Rising Time Schemes in Babyloian Astronomy
3.1, 2017, Prof John Steele notes an assumption
from Mul Apin texts that the Solstices and
Equinoxes ‘take place on the 15th day of Months
I, IV, VII and X in the schematic calendar’.
Assuming that the months numbered are real lunar
months these records show that there would have
been 3 months of 30 days between the Vernal
equinox and the Summer Solstice. If it was Full
Moon on the 15th of the 1st month it would be Full
Moon on the 15th of the IV month, on the 15th of
the VII month and on the 15th of the X month.
5. THE VEDIC ALGORITHM FOR MEASURING
THE TIME OF MOONRISE EACH DAY
For early Vedic astrologers and
astronomers for whom special attention was given
to the movements of the Moon an additional
refinement was developed. In India sunrise or a
time close to dawn was chosen for the start of a
new day. It was different with Middle Eastern
traditions where sunset could be regarded as the
time to start not only the new day but the new
month as well. Since an Indian day was divided
into 30 muhūrtas they realised that if on the 1st
day of the month the (invisible) Moon was rising
just after the Sun then the next day the Moon
would be rising 48 mins or exactly one muhūrta
later. On the third day the Moon would rise in the
3rd muhūrta and so on until on the 15th day it would
be the Full Moon would be rising in the 15th
muhūrta. This system would have been invaluable
for Indian astrologers wishing to enter the position
of the Moon into their astrological calculations.
The date of the month would act like an algorithm
which would always provide a check for the time
of Moon rise for every day of the month. With the
30 day month of the Vedic calendar this system
would have worked perfectly.
A discussion of the past use of the 360 day
year would be incomplete without mention of the
strange figures from the Pa–casiddhāntika (see
Michael Reade, SIS, Review). The tables in this
text provide two clear sets of records for the
synodical periods of the three outer planets,
Saturn, Jupiter and Mars and the two inner planets
Venus and Mercury. The tables expressed in days,
provide sets of figures consistent with an Earth
with a solar year of exactly 360 days. Modern
astronomers reluctant to accept such a possibility
insist that we should presume that the tables should
be interpreted as being measured in degrees
despite the authors clear intentions.
If the figures in Pa–casiddhāntika come
from true astronomical observations they provide
special information. The tables could be correct
if a 360 day orbit had been derived from a slower
spin rate for planet Earth but they do not match
the expected figures if a 360 day year had resulted
from a change to the Earth’s orbit. The figures
372.6 and 393.3 days would still be correct for
the outer planets Jupiter and Saturn but the 575.6
day figure for Venus could no longer apply. If the
Earth was on a reduced orbit the time taken to
circle the Sun would be shorter, so the inner planets
would take more time to catch up to complete their
synodic cycles. Instead of Venus taking 8 fewer
days to catch up with the Earth, it would take 8
additional days so Venus would need close to
592.4 days, or 16 days more to complete its
synodic cycle than the figure from the Hindu
tables.
6. DATING THE INTRODUCTION
360 DAY VEDIC YEAR
OF THE
If the 360 day calendar was such an
integral part of the Vedic traditions and we could
discover when the 360 day year was first
introduced it should help to date the Vedic era. In
Assyrian and Babylonian records the combined
elements of the 360 day Mul Apin calendar start
to appear in the records from Ur III. If dates for
HISTORICAL NOTE: THE ORIGIN OF THE 28 NAKS. ATRAS IN EARLY INDIAN ASTRONOMY
Ur III are correct this would have been towards
the end of the 3rd millennium or around 2,200 BCE.
We know that Classical writers claimed that a 360
day year without intercalary months was used by
the Hyksos rulers in Egypt during the 17th dynasty.
It had also been noted that the Ebers Papyrus from
the early 18th dynasty had months of 30 days and
a year of 360 days without intercalation
(Velikovsky, pp 316 – 32). Numerous Classical
references state the 360 day solar year continued
to be used until around 700 BCE when it was
finally set aside by Numa one of the first Kings of
Rome.
The synchronised 30 day lunar month of
the 360 day calendar may have had a much shorter
life than the 360 day solar year. Clube and Napier
(1982, p. 231), claimed that the 18th Dynasty
Egyptian Pharaoh Amenhotep I had to make
substantial changes to the lunar calendar to try to
re-establish its connections with the seasons and
solar year. We can date Amenhotep I as he reigned
in Egypt a generation or so before the catastrophic
eruption of Thera. We have dates from tree ring
analysis and carbon dating which point to 1628
BCE. If correct this indicates Amenhotep would
have revised his Egyptian lunar calendar in about
1700 BCE. From this time forward Bronze Age
lunar calendars become increasingly inconsistent
and chaotic until they were finally revised at the
end of the Bronze Age.
Babylon didn’t become an established
power until later but the Babylonian Enuma Elis
Creation texts describe similar themes and
calendar cycles to those found in Mul Apin. A
feature of these creation texts was an assumption
for the emergence of Jupiter as the pre-eminent
astral deities. The introduction of a 12 year Jupiter
cycle common to Assyria, India, and China could
also have been closely linked with the introduction
of a calendar in which each of the twelve months
would have been identified with one of the12 steps
making up the 12 year Jupiter cycle.
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If the 360 day year was discarded in 700
BCE a new list of 27 lunar mansions could have
been introduced in India at the same time. The
nakatras linked with the Winter Solstice and
Vernal Equinox could also have been rebooted or
reassigned in accordance with precession and the
prevailing zodiacal signs. (See Maunder and
Maunder)
7. CONCLUSIONS
I have tried to check how the so called
model or schematic calendar was applied by Indian
and Assyrian astronomers. In India the 360 day
year and 30 day month underpinned almost all
astronomical developments in Vedic times. It was
not used as if it was a schematic or even virtual
calendar it was used as if it represented observed
astronomical reality. In part because of a focus on
daily lunar divisions of the zodiac it was applied
far more rigorously and more clearly than the
Assyrian and Babylonian equivalents. Writing in
‘Calendars and Years’ edited by John Steele, Lis
Brack Bernsen (pp.83-100) proposes that
originally the Babylonian 360 day year and 30 day
month had been derived from an early 30 day pig
rationing scheme (p.92). This seems improbable
but so does the alternative that the 360 day
calendar was employed in Vedic times because a
slower rotation of the Earth’s on its axis produced
a Solar year with only 360 days.
Back in the 1960’s it was believed past
rates of rotation for the Earth could be measured
through analysis of growth rings in fossil coral
(John Wells 1963). However like manned lunar
exploration since the sixties, useful advances for
rotation data from fossil and coral and shell fish
has stalled. Recently new studies have shown, that
at least for one creature, an analysis of daily and
monthly rings should resolve this problem and
allow us to measure in days the length of past
monthly and annual cycles (Viola Warter and
Wolfgang Muller). Giant Clams can grow up to a
meter in width, weigh 200 kg and live for decades.
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Their unusual life cycle provide not just daily and
monthly lunar tidal rhythms but additional diurnal
growth increments. Rahman and Cowx in a study
of the incremental growth rings in the otoliths of
Hisla Shad went a long way towards
demonstrating that the number of days in a lunar
cycle can be accurately measured for modern
specimens.
An analysis of growth rings for Giant
Clams from the Miocene era until the Bronze Age
should reveal the lunar cycles for our recent
geological past. Later fossils should reveal
whether any substantial disturbances happened in
historical times. The development of accurate
historical tree ring analysis by Prof Michael Baillie
of Queens Belfast revolutionised archaeological
studies and dating. Perhaps a new impetus could
be provided for Bronze Age studies with the
introduction of effective historical growth ring
analysis from these gentle giants of the tropical
seas. If we take recent studies of Giant Clams by
Warter and Muller, 2016 there is every indications
that their daily and monthly growth rings should
provide an accurate record for pre Iron Age lunar
astronomical cycles.
As noted at the beginning of this paper I
believe the original list of 28 nakatras was
derived from the 27.69, or 27.7 days that the Moon
would have taken to complete a Vedic sidereal
month. Then how can we be certain that the
original older list of 28 lunar mansions was not
simply achieved by rounding upwards from the
27.3 days for our modern sidereal month?
Fortunately, we can. The Hindu records express
the total time taken to complete the Vedic sidereal
cycle in Indian muhūrtas. These time division
similar to the hours used for Western time keeping
except that while we have 24 hours in a Gregoria
day, there are 30 muhūrtas in an Indian day, and
each muhūrta represented 48 mins. This means
that for data derived from the Vedic calendar the
basic time unit of 1 muhūrta would have exactly
matched 1/30th of a day or the time by which (on
average) the rising of the Moon would have been
delayed each day.
Taking the total Hindu number of 831
muhūrtas for the Moon to complete a 360 degree
sidereal orbit we would have;
831 / 30 = 27.7 days
Weixing notes 831 is the number of
muhūrtas that has been passed down through
Hindu texts (Niu Weixing, 1997) and it confirms
that the original list of 28 muhūrtas must have
originated from the 27.7 days it was anticipated
that the Moon would take to encircle the Earth to
complete a sidereal lunar cycle . The precision of
the 831 sidereal measure demonstrates that the
methods applied by early Hindu scholars could
be both consistent and accurate when applied
within the context of a year of 360 days and the
360 day year was clearly the only year that Vedic
astronomers and astrologers recognised at the time
of the Early Bronze Age in 2,000 BCE.
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Antiquity of Vedic and Harrapan Traditions, Indian
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the Universal Deluge, Talk given before the Royal
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Rejoinder by A K Bhatnagar, Delhi
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The Research note analyses the 360 day
calendars devised by many ancient cultures,
namely Babylonian, Vedic Indian, Chinese and
similar calendars possibly used by Mayan and
other south American cultures. Considering the
common 360-day length of the calendar year then
used globally, and the number of lunar Mansions
or nakatra as 28 as used by early oriental
astronomers, he puts forth a hypotheses that the
solar year actually consisted of 360 Earth-days.
In order to accommodate this length of the year,
he suggests that the day was of slightly longer
duration, implying a slower rate of spin during
that period in Earth’s history. He makes out a case
for a study based on the growth rings for Giant
Clams from the Miocene era until the Bronze Age
that may reveal the lunar cycles for the recent
geological past. In his opinion, their unusual life
cycle may provide daily and monthly lunar tidal
rhythms and other useful information.
In this connection, a reference is invited
to the work of Abhyankar (1993, 1998 and 2005)
and Bag (2015) which shows the evolution of the
Calendar in India from the Vedic times. They show
that the earliest Vedic calendar was tropical in
nature consisting of 360 days counted from Winter
Solstice. The marker for the event was heliacal
rising of Aśvinī nakatra (star β Arietis). That the
months were not lunar is evident from the oldest
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INDIAN JOURNAL OF HISTORY OF SCIENCE
tropical month names ‘arua, aruaraj…’ etc.
(Taittir. Brāh. 3.10.1.4) and the other set of tropical
month names ‘madhu, mādhava…’ etc. (Taittir.
Sah. 1.4.14). It is also shown that a correction
of 5 or 6 days called ‘atirātra’ was applied initially
around the Summer solstice time with arrival of
the first rains of the Indian summer monsoon at
the site of observation . Later this correction was
applied as an additional month (mahasvan,
intercalary month) of 30 days after a cycle of 5
solar years to keep the year beginning in step with
winter solstice. The lunar motion was also
observed at the same time but was not part of the
calendar. Later, the 28 and 27 nakatra divisions
were followed for both the sun and the moon. It is
shown by them that such a calendar would have
been followed for about a 1000 years after which,
the marker for year beginning changed to the full
moon in Citra nakatra as precession had moved
β Arietis away from WS. This gave rise to the lunisolar calendar in India, which has undergone
numerous changes since then. It is thus clear that
the 360 day year length was used for convenience
of calculation, which had a correction applied to
it so that the average length of the year remained
around 365 or 366 days. The actual period of
earth’s revolution and rotation were more or less
the same as they are now (within the accuracy of
naked eye observations).
Further, the present studies based on
records of ancient eclipses (from 720 BCE) show
that the length of the mean solar day increases at
an average rate of +1.8 ms per century. Even the
rate predicted on the basis of tidal friction is +2.3
ms per century. These are in the sense of Earth’s
spin slowing down from that time to the present.
The author’s note suggests that the Earth’s spin
rate was actually slower than the present rate by
an amount such that the Earth’s orbital period
would be 360 days. It works out to be about 24h
21m. Our present understanding about the
underlying causes such as tidal friction and from
an effect due to time-varying magnetic dipole of
the Earth or other geophysical changes in Earth’s
core, all put together would not be able to explain
the much larger change in the Earth’s rotation rate,
in reverse order, as required under his paper.
The note however does not provide any
direct evidence of a longer Earth day during the
Vedic period.
BIBLIOGRAPHY
Abhyankar, K D. A search for the Earliest Vedic Calendar,
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Abhyankar, K D. Earliest Vedic Calendar, Indian Journal
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Bag, A K. Early System of Nakatras, Calendar and
Antiquity of Vedic & Harappan Traditions, Indian
Journal of History of Science, 50.1 (2015):1-25.