Astronomical Dating of Rigveda

Ashok K. BhatnagarFormer Director, Positional Astronomy Centre

Former Additional DG, India Meteorological Department

Email: bhatnagar.ashok@gmail.com

"The Indus-Sarasvati (Harappan) Civilization vis-a-vis The Rigveda“,

Draupadi Trust, New Delhi, 26-28 March, 2015

The science of Astronomy is as old as

human civilization.

It has resulted from thousands of years of

human observation and thought

Natural cycles that affect human life most :

alternation of daylight and night

recurrence of the phases of the moon and

recurrence of the seasons

Astronomy

Dating of Astronomical References

Frequent references to these cycles in

ancient scriptures pointing to development of

a reliable calendar for prediction of :

seasons and

moon’s phases

It is possible to simulate the described

phenomena by applying modern

astronomical knowledge and tools; thereby

determine the period of these texts.

Sunrise PointSUMMER SOLSTICE

JUNE VERNAL EQUINOX

MARCH WINTER SOLSTICE

DECEMBER

ΔA ΔANorth SouthE

Sunrise Point and seasonal cycle

Amplitude:

ΔA = cos-1 (sin δ / cos φ) - 90º

Because the changing

Declination δ of the Sun

causes the seasons,

azimuth variation can

be used to mark them

Such variation was observed

in the Megalithic.

In India, we have plenty of

evidence of such observations

that take us to 9000 years

BP, almost to the start of the

Holocene.

Astronomical References In Rig-Veda

• Rig-Veda is considered as the most ancient Sanskrit text in India

{The Rig Veda, Translator Ralph T.H. Griffith, (1896),

Shriram Sharma Acharya. Rig-Veda Samhita, Hindi translation, Haridwar 2002 }

• Astronomical phenomena described in Rig-Veda hold clues to the time of composition of the respective verses

• Pioneering work was done by

S. B. Dikshit, „Bharatiya Jyotisa Sastra’ (1896), (Marathi).

K. D. Abhyankar (Bull. Astron. Soc. of India,26, 61-66, 1998)

Early Astronomical References

यददवा यतयो यथा भवनानयपिनवत |

अतरा समदरआगळ हमा सययमजभतयन || When, O ye Gods, like Yatis,

ye caused all existing things to grow,

Then ye brought Sūrya forward

who was lying hidden in the sea. Rig Veda 10.72.7

उत सय न उपिजामरववया कपवरपहिः िणोत बधनयोहवीमपन| सयायमासा पवचरनता

ददपवपिता पधया िमीनहषी असय बोधतम ||And may he too give ear, the Sage, from far away, the Dragon of

the Deep, to this our yearning call.

Ye Sun and Moon who dwell in heaven and move in turn,

and with your thought, O Earth and Sky, observe this well. Rig Veda

10.92.12एक एवापिबयहधा सपमदध एकिः सयो पवशवमन परभतिः |

एकवोषािः सवयपमद पव भातयक वा इदपव बभव सवयम ||

Only one sun is the lord of the universe;

one dawn gives light to the universe.Rig Veda 8.58.2

The Lunar cycle

नवो-नवो भवपत जायमानो.अहना कतरषसामतयगर | भाग दवभयो पव दधातयायन िर चनदरमापसतरतदीरयमयिः ||

He, born afresh, is new and new for ever

Ensign (flag or mark) of days he goes before the Mornings

Coming, he orders for the Gods their portion.

The Moon prolongs the days of our existence. Rig Veda 10.85.19

Rules for Early Calendar

सतयनोततपभता भपमिः सयणोततपभता दयिः|

ऋतनाददतयापसतषठपनत ददपव सोमो अपध पितिः||Truth is the base that bears the earth;

by Sūrya are the heavens sustained.By Law the Ādityas (constellations/sun‟s path) stand secure,

and Soma (Moon‟s path?) holds his place in heaven.Rig Veda 10.85.1

यत तवा दव परपिबपनत तत आ पयायस िनिः |

वायिःसोमसय रपिता समाना मास आकपतिः ||

When they begin to drink thee then, O God, thou swellest out again.

Vāyu is Soma's guardian God. The Moon is that which shapes the years.

Rig Veda 10.85.5

Rig-Vedic Calendar

वद मासो धतवरतो दवादि परजावतिः | वदा य उिजायत ||

Dhratavrata (Varuna) knows the twelve moons (months) with their progeny:

He knows the moon of later birth (intercalary month). Rig Veda 1.25. 8

दवादिार नपहतजजराय ववयरवत चकर िररदामतसय |

आ ितरा अि पमथनासो अतर सपत ितापन वविपतशच तसथिः ||

Formed with twelve spokes, by length of time, unweakened,

rolls round the heaven this wheel of during Order.

Herein established, joined in pairs together,

seven hundred Sons and twenty stand, O Agni. Rig Veda 1.164.11

दवादि परथयशचकरमक तरीपण नाभयापन क उतपतचकत |

तपसमनतसाक पतरिता न िङकवोSअरवितािः षपिनयचलाचलासिः ||

Twelve are the fellies, and the wheel is single; three are the naves.,

what man hath understood it?

Therein are set together spokes three hundred and sixty,

which in nowise can be loosened.

Rig Veda 1.164. 48

Seasons Caused by Sun: the two half-years

दव त चकर सय बरहमाण ऋतथ पवदिः |

अथकचकर यदगहा तददधातय इद पवदिः ||

The Brahmans, by their seasons, know, O Sūrya,

those two wheels of thine:

One kept concealed, those only who are skilled

in highest truths have learned. Rig Veda 10.85.16 िवायिर चरतो माययतय पिि कळनतय िरर यतोधवरम |

पवशवानयनयो भवनापभचि ऋतनरनयोपवदधजजायत िनिः ||

By their own power these Twain in close succession

move; They go as playing children round the sacrifice.

One of the Pair beholdeth all existing things; the other ordereth seasons and is born again.

Rig Veda 10. 85.18

Sun’s Motion, Seasons and Length of the Day

(Specific mention of Uttarayana or Udagayana and

Dakshinayana found only from Shat. Brah 2.1.3 and

Narayana Upanishad Anu. 80, but clearly defined from

Siddhanta Period as prevalent today).

तसमादाददतयिः षणमासो दपिणनपत िडततरण |

The sun moves towards the south for six months and

north for another six months. Taitr. Sam. 6.5.3

इपषरण त मनसा सतसय भिीमपह पितरयसयव रायिः |

सोम राजन परण आयपष तारीरहानीव सयो वासरापण ||

May we enjoy with an enlivened spirit

the juice thou givest, like ancestral riches. O Soma, King, prolong thou our existence as Sūrya makes the shining days grow longer.

Rig Veda 8.48.7

Year- सवतसर and ऩररवतसर बराहमणासः सोममनो वाचमकरत बरहम कनवनतः पररवतसरीणम | अधवरयवो घममयणः मसषववदाना आववरयवषनत गहरा न क चचत || These Brahmans with the Soma juice, performing their

year-long rite, have lifted up their voices; And these Adhvaryus, sweating with their kettles,

come forth and show themselves, and none are hidden. Rig Veda 7 .103. 8

दवहहतत जगऩरदयवादशसर ऋत नरो न पर ममननतरत | सवतसर पराववरागतारा तपता घमाय अशनवत ववसगयम || They keep the twelve month's God-appointed order,

and never do the men neglect the season. Soon as the Rain-time in the year returneth,

these who were heated kettles gain their freedom. Rig Veda 7.103.9

Cycle of Seasons as measure of time- Year

शत जीव शरदो वधयमानः शत हमनताञछतमवसनतान | शतममनराघनी सववता बहसऩततः शतारषाहववषम ऩनदयः ||

Live, waxing in thy strength, a hundred autumns, live through a hundred winters a hundred springs,. Through hundred-lived oblation Indra, Agni, Bṛhaspati, Savitar yield him for a hundred! Rig Veda 10. 161.4

Atirattra correction to Year

बराहमणासो अततरातर न सोम सरो न ऩणयममरतो वदनतः | सवतसरसर तदहः ऩररवठ रन मणडकाः परावषीण बरव ||

As Brahmans, sitting round the brimful vessel,

talk at the Soma-rite of Atiratra,

So, Frogs, ye gather round the pool to honour this day of

all the year first of Rain-time. Rig Veda 7.103. 7

Year (Samvatsara): Seasonal- determined from

observation of position of rising sun and at noon

Year had 360 days and 720 day/night.

(Rig Veda 1.164.11,48)

12 solar Months of 30 days each (Aruna,

Arunaraj etc -Tait. Samh. 3.10.1 and Madhu, Madhava

etc- Tait. Samh.1.4.14 )

Leap days (Atiratras)- 4, 5 or 6 days added in the

middle of the year of Samvatsarasatra around start of rains. (Rig Veda 7.103.7, Tait. Samh. 7.1.8)

Practice changed to having an intercalary month

of 30 days (after every 6 years) (Rig Veda 1-25-8)

Rig-Vedic Calendar

How did they decide Year –Beginning?

Half years: Uttarayana begins at WS (as

also the year); Dakshinayana begins at SS

(Visuvadin).

Heliacal rising of certain stars (Asvini)

was used as Marker for year beginning.

There are 53 refs. in Rig-Veda eg. 5-77-

1/2; 1-46-14; 7-69-3/2 offering prayers to

Asvinis (Aries ) relating them to the Sun,

the Dawn and Season of agricultural

produce.

Star Observations

रवोरषा अन पिर ऩररजमनोरऩाचरत | ऋता वनथो अकतमरः || O circumambient Aśvins, Dawn follows the brightness of

your way: Approve with beams our solemn rites.

Rig Veda1.46.14 रदषो रामस रानना स सरण रोचस | आ हारमषशवनो रथो वततयरायतत नऩायरम ||Thou, Dawn, approaching with thy light shinest together

with the Sun,

And to this man-protecting home the chariot of the Aśvins

comes.

Rig Veda 8.9.18

Asvins (Asvini) sighting as marker for Year Beginning

Tropical or

Seasonal Year

365.24219 days

Sidereal Year

365.25636

days.

Longer than

tropical year

by about 20m

due to

Precession

Precession- Vernal Equinox and Winter Solstice through ages

Equinoxes move westward along the ecliptic relative to

the fixed stars, at the rate of about 50.3 seconds of

arc per year. Past observations of Equinox/Solstice

can help determine their date using precession rate.

Winter Solstice

Today

Winter Solstice

9000 years ago

Spring Equinox

9000 years ago

Winter Solstice

Today

Vernal Equinox 2011

Psc

Summer Solstice 2011

Tau

Winter Solstice 2010

Sgr

Tau

Vernal Equinox 8000 BC

Cnc

Sky simulation softwares :

Utilise high precision data on positions of stars (HIPPARCOS)

Solar system ephemeris (DE200/HORIZONS of JPL, NASA,

USA and VSOP87 of France)

The time can be set to generate views of sky in future or past

Very high planetary accuracy of 0.1 - 1 s, over 2000 BC to 4000

AD. Beyond that accuracy falls. We need to match only naked

eye observations of remote past. Low accuracies will suffice.

The date of Vernal Equinox remains fixed around 21-23 March

in „Planetarium Gold‟ over millenia; it keeps drifting in

„Stellarium‟ from 21 March during 2011- 1582 to 2 May in 5000

BC and so on.

These can be used to simulate the phenomena described in

ancient texts to help determine their dates.

Sky Simulation for Rig-Veda events

वव वा रथो वधवा रादमानोऽनताषनदवो बाधत वतयतनभराम |Rig-Veda 7-69-3/2

“Your cart on which your spouse is wont to travel

marks with its track the farthest ends of heaven”

This shows that the Ashvinis (Aries) represented the

southernmost point of the sun‟s amplitude on the

horizon-the Winter Solstice (WS).

This implies an ecliptic longitude of 270◦.

Asvini‟s (Alpha Arietis) longitude(1950) is about 33◦

Allowing for the change due to precession @ 50‟‟.3

per year, we arrive at a time about 9000 years

BP.

The sky simulated over Delhi shows WS in Aries

on 19 December, 7001 BC.

Earliest Vedic reference of Winter Solstice, 7000 BC

Winter Solstice occurred in Aries (Asvini Nakshatra)

on 19 December, 7001 BC . Sky at 07:15 Hrs (RgVeda 5:77.2, 7:69.3)

परातरायवाणा परथमा रजथव ऩरा गधरादररषः वऩबातः |परातहहय रजञमषशवना दधात परशसतत कवरः ऩवयराजः ||

Rgveda 5-77-1 & 2

“first worship those who come early in morning. Let the twain drink soma before others. The sages of old extol that the Ashvins claim the sacrifice at daybreak.”

The above line refers to „heliacal rising‟ of Ashvinis (Aries) at WS, i.e., the first sighting of Ashvinis on the eastern horizon after Winter Solstice, just before sunrise.

The event was used as marker for the year beginning as shown in the sky view over Delhi on 5 January, 7000 BC.

Earliest Vedic reference of Winter Solstice, 7000 BC

Heliacal rising of Ashvini Nakshatra, marking the year beginning ; Jan 05, 7000 BC, 0649 hrs

Horizon

कवठो दवावषञचनारदरा हदवो मनावस |

तचछरवथो वषणवस अतरतरवायमा वववासतत ||

कत तरा कह सशरता हदवी दवा नासतरा | Rig-Veda 5-74-1 & 2/2

“Where in the heaven are you today, Gods, Ashvins, rich

in consistency? Hear this, ye excellent bestowers:

Atri invites you to come. Where are they now? Where

are the Twain, the famed Nasatyas, gods in heaven”.

Precession had moved the WS to Revati by 6000

BC. Ashvinis were no longer rising before the Sun

at WS.

The second stage of Vedic Calendar- 6000 BC

Bright star Chitra (Alpha Virginis) on

opposite side (Western horizon) began to be

used as a new marker for the year beginning.

Later, a full moon in Chitra heralded the

lunar month naming system - Chaitra,

Vaisakha etc of Luni-Solar Calendar ,which

finds explicit mention in :

चितरापणणमास दीकषरन मख वा एततसवतसरसय |Taitr. Samh 7.4.8.

“Chitra full moon is the mouth of the year”

Vedic Calendar- 6000 BC

Chitra

(α Vir)

Winter

Solstice

Full moon in Chitra at Winter Solstice on 19 Dec 6000 BC

as the new time marker for the year beginning

The year (Samvatsara/Parivatsara) in Rig-Vedic

time was solar tropical (based on seasons), had two

halves, 12 solar months of 30 days each, had 360

days with „Atiratra‟ correction of 4 to 6 days in the

middle of the year at the beginning of rains.

The earliest reference of year beginning at Winter

Solstice found in Rigveda corresponds to the date

19th December, 7001 BC and the „marker‟ for the

event- „heliacal rising‟ of Ashwini Nakshatra (Aries)

occurs on 5th January, 7000 BC.

Concluding Remarks

In the second stage, when Aries had moved away

from WS due to precession, Chitra (Alpha Vir.)

opposite the Sun in Winter Solstice was used

from around 6000 BC as the new time marker

for the year beginning .

Concluding Remarks...

Indian Nakshatras

GENERAL PRECESSION

The combination of the gravitational effect of Sun, moon and planets on the orientation of the earth in space is called general precession

Equinoxes move westward along the ecliptic relative to the fixed stars, at the rate of about 50.3 seconds of arc per year, opposite to the motion of the Sun along the ecliptic

As a result of the precession, the apparent position of the Sun relative to the backdrop of the stars at some seasonally fixed time, say the vernal equinox, slowly regresses a full 360° through all twelve traditional constellations of the zodiac in 25,772 years, at the rate of about 50.3 seconds of arc per year or 1 degree every 71.6 years.

PRECESSION OF EQUINOX-25,772 YEARS