Vedic Period 4

                        Astronomy During the Vedic Period-4

                                          Nakshatra नक्षत्र

Nakshatras, as generally understood by all, is a group of stars in the sky used for astrological purposes. Why were they formed or created?  and What is their purpose? and is what we should know. 

The Vedic people first looked at the Sun and Moon to calculate time. The Moon was the basis of the heavenly clock. Therefore it was necessary to know the location/position of the Sun,  Moon and equinocal points in the Sky. These people regularly performed rituals and yagasयज्ञ and to know the appropriate time to perform these rituals, they had to know the exact position/ Location of the celestial object.

Today it is easy to know the position with the help of a celestial coordinate system. In the absence of such a system, a fixed/stationary reference frame was required to ascertain the location/position of a celestial object. 

Nakshatras provided this reference frame, in the sky, to the observers. All our Vedic works, including epics of Mahabharat, and the timing of events are given with reference to Nakshatras. 

The names of months in our Hindu calendar are based on these Nakshatras, this is because the nakshatra in which the full Moon was observed that month was named on that Nakshatra. 

Rashi/ Zodiac signs were adopted into Hindu astronomy around 200 BCE-300CE

The nakshatras are images of earthly objects. Some nakshatras have derived their names from their resemblance to particular figures. There are a few nakshatras who have derived their names differently.

A verse from Taittriya Brahman, 2.7.18.3

प्रवाद्ग्वा अग्रे क्षत्राण्यातेपुः ।॥ तेषामिंद्र: ॥ क्षत्रण्यादत्त ॥ नवा इमानि क्षत्राण्यभ्‌रवान्नितिं ।॥ तन्नक्षत्राणां नक्तत्रत्वं ।।

 derives  the word नक्षत्र as , those which are not,क्षत्र (moveable) are  नक्षत्र. This is as defined in Nirukta, explanation. There is another verse which describes नक्षत्र as the abode of Gods.

Nakshatras, also as stars in general are mentioned in Atharva Samhita 

अप त्ये तावयो यथा नुक्षत्ना यत्यक्तुभिः ॥ सुराय विदवचक्षसे ॥

~The stars and the night escape like thieves on the approach of  the Sun"

 Rk Samhita and Atharva Samhita, mention the word नक्षत्र as stars in general. Post-Vedic works also describe it as stars in general, including those in the Moon's path.

अथो नक्षत्राणामेषामुपस्थे सोम आहितः ॥।

~"The Moon is placed among the stars"~

Another metaphoric, description of nakshatra is found in Taittriya Brahman 1.5.2 

 सलिलं वा इवमंतरासीत्‌ । यदतरन्‌ ॥ तत्तारकाणां तारकत्वं । यो वा इहं यजते । अमुं स लोकं नक्षत्र ॥ तन्क्षत्राणां नक्षत्रत्वं ।॥। देवगृहा वं नक्षत्राणि ॥ य एवं वेद ॥ गृह्येवभवति ।\ यानि वा इमानि पृथिष्याहिचत्र्णण ।॥ तानि नक्षत्राणि ।॥ तस्माददलीलनामं शिचित्रे \॥ नावस्येन्नयजेत ॥ यथा पापाहे कुरुते ॥ तादृगेव तत्‌ ॥ |

                                                                    

which says 

"There was water in the centre. The tarakas are said to possess the prosperity of tarakatva(protectiveness) because they floated and saved themselves. He who performs oblation here goes (naksate/नक्षते) to that world. Hence the nakshatra significantly so-called, are the houses of Gods. He who knows this becomes the owner of a house. the nakshatras are the images of earthly objects. Hence a rite and an oblation should not be performed on an ugly nakshatra. It gives the same result as that performed on an inauspicious day"

This derivation traces the word to the root ' naksa'/नक्ष (to go). Virtuous people will go to heaven and become nakshatras. It puts out the idea that the nakshatras are the houses of Gods. (God here means planets, refer to my blog " Vedic Period -3")

Taittriya Samhita 7.5.25 mentions nakshatras as stars in general and in the Moon's path.

यो वा अश्वस्य मेध्यस्य शिरो वेद शीषण्वान्देध्यो भवत्युषा वा अश्वस्य

 मेध्यस्य क्ञिरः सूयंश्चक्षवातः प्राणव्चं रमाः भत्रं दिशः पादा अवां तरदिज्ञाः 

पशंवोऽहोरात्रे निमेषोधंमासाः पर्वाणि मासाः संधानान्युत्वोऽगानि

संवत्सर आत्मा रहमयः केशा न॑शत्राणि रूपं तारका अस्थानि नभो मासानि 

To summarise ~ "Dawn is the head of the horse. Heaven is his eye. The year is his soul. His form are the nakshatras and the stars are his bones”.

There are numerous definitions and derivations of Nakshatra evolved in the later periods. Something like 

 "नचरति, नक्षरति, अथ नक्षत्रति"

~They neither move nor deviate; they do not get destroyed and their greatness never diminishes over time; hence they’re known as nakshatras.~

Names of all nakshatras and their ruling deities are mentioned in various texts. Some describe them, some describe the origin of their manes etc.

Taittriya Samhita 4.4.10 mentions the names of all 27 nakshatras and their deities.

 कृत्तिका नक्षत्रमग्नि्वताग्नर्च स्थ प्रजापतेर्धातुः सोमस्यचं त्वा रुचे त्वा द्युते स्वा भसेत्व्ा ज्योतिषे त्वा रोहिणी नक्षत्रं प्रजार्पतिदेवता मुगशीषं नक्षत्रेसोमो देवता्रानतरडो  देवता । पुनवेसुमक्षत्रम दितिर्देवता तिर्य नक्षत्र बहस्पतिदेवताधेष नकषत्रेसर्पा देवता मघाग्नक्षत्रं पतसे देवता फल्गनीनक्षत्रसयंमा देवता फलग॒नी भैश्रं भगो देवता हस्तो(शक्षतरेसविता देवताचित्रा  नक्षत्रमिंदरो देवता स्वाती चकषत्रं वारं वता विशाखं क्षत्रमिदराण्नी देवतान्‌ राधां नक्षत्र मितो ॥ एकक 1 { | व देवता रोहिणी ्षत्रसिं द्रो देवता {विचृत्ती न्त्रं पितरो देवताषाढानषत्रमापो देवताषा्ा 1 दड्नकषर्ज विश्वेदेवा देवता श्रोणर नक्षत्रं विष्णुर्देवता शविष्ठा नक्षत्रं वसवो देवता शतभिषङनक्षनमिंदरो देवता श्रोष्ठपर्वा नक्षत्रमजएकपाहेवता प्रोष्ठपद न॑क्षत्र्माहर्बुध्नियो देवता रेवती त्त पुषा  | दे वताअश्विनी नश्षत्रसरिवनौ देवतापभरणीनं क्षत्रं यमो देवता पूर्णापश्चाद्यत्ते देवा अदधुः ॥

Atharva Samhita 19.7.1 mentions 

वचिन्राणि साकं दिवि रोचनानि सरीसृपाणि भुवने जवानि ¦ 

अष्टाविज्ञं सुमतिमिच्छमानो अहानि गीर्भिः सपर्यामि नाकम्‌ 

सुहवं मे कत्तिका रोहिणी चास्तु भद्र मृग्शिरः शमाद्रा।

पुनवेसु सूनृता चह पुष्यो भनुराश्लेषः अयनं मघा मे 

The first verse says" I being desirous of welfare, worship the heaven with the speeches, because 28 clusters of stars, like wonderful illuminating lights arranged in the form of nimble serpents, shine in the sky"

This shows that nakshatras are 28 in number. Taittriya Surti has mentioned Abhijit Nakshatra several times, however, the later texts mention only 27 Nakshatras. Why the 28th Nakshatra was dropped? No explanation is found. It appears that it was for ease of calculation?

Most of the verses, during the Vedic period, which describe the nakshatras start from the Nakshatra कृत्तिका(Pleiades). That means the list of nakshatras commenced with कृत्तिका as the first nakshatra during that period.

The Shatapatha Brahmana mentions that the कृत्तिका (Pleiades) "do not swerve from the east". This would have been the case with precision at 2950 BCE and was true also about 2000 BCE and was within 8-13 degrees around 8th to 6th BCE.

"Why should the list start with a specific nakshatra?" As previously mentioned in the Vedic Period blogs 1-3, the start of the year was based on either the Vernal Equinox (VE) or Winter Solstice (WS). To determine the exact position of VE or WS, the reference frame of Nakshatras was utilized since it's simple to identify the position of the equinoctial/solstitial colure using the reference frame of Nakshatras.

The Kritikadi system was in force during the Vedic period, meaning the Vernal equinox was in kritika nakshatra and the Winter solstice was in Sharavan/Dhanishta nakshatra. Hence the list started with  कृत्तिका Nakshatra.

 With the help of appropriate software, we can interpolate this conjunction backwards to know the exact date of this period. The diagram below explains this.

As of date, the list of nakshatras starts with अश्विनी and is known as अश्विनादि system. However,अश्विनी Nakshatra is not at the Vernal equinox.

Due to the precession of the equinoxes, we see the conjunction of रेवती/उत्तराभाद्रपद nakshatra with the vernal equinox as of date.

 It takes approximately 900 years for the nakshatra to shift from the equinoctal colure.

                            Origin of the names of a few nakshatras.

The names,पुनर्वसु (Castor and Pollux),चित्रा(Spica), मघा (Regulus)and रेवती(Zeta Piscium) did not indicate nakshatras but were already in use in a different sense. 

पुनर्वसु(a twin star)

अग्नीषोमा पुनवंसु अस्मे धारयतं रथिं ॥     ऋ. सं. १०,१६. १.

 ~is quoted as two Gods, who give shelter to those who offer prayers.~

 A dual form word for a dual star (quite remarkable as to how ancient observers identified correctly), they are seen in Gemini (मिथुन) zodiac sign. Did the sign Gemini get the twin status from this?

Chitra Magha(Regulus), the mighty, is used as chitramagha to denote " one having wonderful wealth. In almost all cultures/folklore this star is denoted as a king and mighty.

रेवती(Zeta Picium) means one possessing wealth and being prosperous.

These names were applied to Nakshatras, due to their munificence, and loveliness.  The people would have experienced, imagined or noticed these characteristics.

Aiteriya Brahaman mentions some legends regarding रोहिणी (Aldebaran),मृग(Lambda Orionis), and मृग व्याध (Sirus). The legends of Rohini, Mrigashirsha, Prajapati and antelope hunting all describe the cluster of stars around the Orion मृगशीर्षconstellation. All cultures have similar stories and legends regarding the Orion.

Taittriya brahman 1.5.2.2 gives out the vision of nakshatriya prajapati as, 

यो वं नक्षत्रियं प्रजापत्तिं वेद ॥ उभयोरनं लोकयोविदु : ॥ हस्त एवास्यं हस्तः ॥

 चित्रा क्षिरः ॥ निष्ट्चा ह्‌ दयं ॥ ऊरू विज्ञाखे ।। प्रतिष्ठान्‌ राधाः ॥ एष वै नक्षत्रियः प्रजापति : ॥

                                                                                                     

~"He who knows nakshatra Prajapati knows him as related to both worlds. Hasta is his hand, Chitra is his head, nistya(Swati) his heart, two Vishakha stars as his thighs, and Anuradha is the place to stand upon. This is nakshatriya Prajapati"~

This description fits the present-day observation, except for the star Swati, which is out of place. This is probably because the Proper motion of this star is faster and hence may have moved out.

Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the centre of mass of the Solar System, compared to the abstract background of the more distant stars.

Origin of the names of अनुराधा (beta Scorpionis) and ज्येष्ठा(Antares, alpha Scorpionis) have been described in Taittriys Brahaman 1.5.2. 

Sayana, in his commentary on this verse, says ' It was a statement by the Gods with reference with the battle with the Demons... "We killed the eldest of them on ज्येष्ठा nakshatra." (Antares is the biggest star in the group, hence the name ज्येष्ठा)

The grammatical number in which the nakshatra names are used helps indicate the number of stars in each group. Mrigashirsha मृगशीर्षः(stars around Orion)and हस्त (group of stars appears as a palm of a hand, hence the name ) are a group of stars, but they are used in singular numbers. 

The singular number nakshatras are 

रोहिणी(Aldebaran),आर्द्रा (Betelgeuse), पुष्य (γ, δ and θ Cancri), चित्रा(Spica),स्वाति(Arcturus),ज्येष्ठा(Antares) ,मूल( ε, ζ, η, θ, ι, κ, λ, μ and ν Scorpionis),श्रावण(α,β and γ Aquilae), शततरका(γAquarii), रेवती(Zeta Picium). Indicating that each of them is a single star.

Nakshatras with dual stars are

पुनर्वसु(Castor and Pollux),पूर्वाफाल्गुनी(Delta and Theta Leonis),उत्तरा फाल्गुनी(Denebola),विशाखा(α, β, γ and ι Librae),अश्विनी (β and γ Arietis)

The balance of nakshatras are plural and have more than two stars.

                                            Saptarishi

The Vedas also refer to certain stars, other than those stars in 27 nakshatras,

अमी य ऋक्षा निहितास उच्चा नक्त" दद्र कुह चिहिवेय्‌: ॥

                                                                                 ऋ.सं. १ २४. १०

~" These Bears which appear to be placed at high elevation at night go somewhere in the day"~ 

( These constellations are popularly known as The Great Bear)

Shatpath Brahaman 2.1.2.4 observes 

सप्तर्षनु ह स्म वे पुरर्षा इत्याचक्षते ॥

~" The Saptarishis were called bears in ancient times"~

And Tandiya Brahman1.5.5 mentions as 

ऊध्वं सप्त ऋषीनुपतिष्ठस्व ॥।

~" Worship the seven sages above"~

Almost all the stars in the Nakshatras are, either the biggest, brighter, twin stars or as a group visible and easily identifiable.

A remarkable feat of Vedic people. It has been proved by various scholars that this Nakshatra system is a Hindu creation. Contrary to the popular belief that it was borrowed from the Chinese system. In fact, it is the other way around. 

____________________________

References

1. SB Dixit " Bhartiya Jyoti's Shastra" Part 1

2. William Brennand " Hindu Astronomy"

3. Ancient Indian Astronomy by RN Iyengar.

4. Ancient Astronomy by Prof TS Kuppanna Shastry

5. Research on Nakshatras by Dr Arjun Pai

6. Mythology of Nakshatras by Arvind Bhagwath

Vedic Period 3

                   

                     Astronomy During the Vedic Period-3

In continuation of the history of Hindu astronomy (do read earlier blogs on the subject). Some mentions of astronomical aspects during the pre-Siddhantic/Vedic period are enumerated. But why were astronomical references found in the Vedas?

The importance of astronomy is stated in Yajurved Vedang Jyotish-3 

वेद: हि यज्ञार्थं अभिप्रवृत्तः कलानुपूर्व्य विहिता च यज्ञः!
तसमद इदं कलाविधानशास्त्रम्
यो ज्योतिषं वेद स वेद यज्ञं

" The Vedas have indeed been revealed for the sake of performances of sacrifices. These sacrifices are dependent on the (various segments of)time. Only he who knows Jyotisha(time calculation)understands the performance of sacrifices"

Interpretation of Vedic texts                                 

Vedic culture personified celestial objects and their actions. Hence the texts carry a background, that has to be deciphered to extract the archaic models of the visible sky. These texts use an allegorical approach to describe the celestial events.

Yaska records three types of interpretations of the Vedic hymns These are अधीयज्ञः(sacrificial), अध्यात्म:(philosophical) अधिदैवः(celestial/divine).

 The use of metaphor is often misinterpreted. The word Soma as perअधिदैवः is Moon, as per अधीयज्ञः is a creeper and as per अध्यात्म:, is manas/mind.

A further difficulty arises, as the Hindu socioreligious pluralistic tradition, which is in constant flux, tends to attribute different meanings to the same word. Hence, some European scholars have termed Vedic texts as mythological or works of fiction. 

Continuing with the astronomical references in the Vedic period 

                                    Divisions of the Day

  The works of धर्म शास्त्र describe the system in which the day was divided into2,3,4,5 and 15 various parts. These are 

2 Parts पूर्वाह्णे,formerhalf अपर्णः laterhalf. 

3 partsपूर्वह्नः, माधयन:,अपर्णः,

4 parts पूर्वह्नः, माधयन:,अपर्णःसयह्नः each part also known as प्रहर,

5 Parts प्रतहःपूर्वह्नः, माधयन:,अपर्णःसयह्नः,

15 parts known as मुहूर्त.

Today we have divided our day into similar parts like Morning, evening, forenoon, afternoon, midday, late evening, early morning, ....etc, and 24 divisions known as hour.

The following lines denote a system of threefold division of the day.

ऋग्भिः पूर्वा दिवि देव ईयते ॥ यजुर्वेदे तिष्ठति मध्ये अहुः ।। सामवेदेनास्तमये महीयते ।॥ वेद रशून्यस्तिभिरेति सूर्यः \।                                                              त. ब्रा. २३. १२

पूर्वाह्लो वं देवानां मध्यंदिनो मनुष्याणामपराह्लः पिर्हृणां ।।               शत. द्रा. २.४. २.८.

" The earlier part is controlled by Gods, the middle one by men , and the later part by Pitris"

Many verses in Taittriya Brahman, Rk Samhita and Atharva Samhita describe the system, of division of the day into various parts, depending upon usage.

There are verses which give out the names of 15 muhurtas. Interestingly some verses do describe the names of 15 muhurta for the night. That means the day and night were divided into 30 parts! (similar to the 24 parts we have today).

These were further divided into 15 sub-muhurtas, later known as 'nadis'

The following verse from Taittriya Brahaman 3.10.1, gives out the names  of 15 मुहूर्त 

चित्रः केतुः प्रभानाभास्त्संभान्‌ ॥ ज्योतिष्मास्तिजस्वानातपंस्तपन्नमि तपन्‌ ।

रोचनो रोचमानः शोभनः शोभमानः कल्याणः ॥।          ते. बृा. ३. १०. १

The texts also give out the names for the 15 muhurtas of the day and 15 for the night in the light half of the month, a total of 30 names. 

Similarly, the texts describe the names of 15 muhurtas for the day and 15 for the night in the dark half of the month.

 Why did the Vedic culture divide a day into 30 parts? Is there any evidence in the Vedic texts that, suggests the Sexagesimal system was used during that time? Ptolemy did use this system. Al-Biruni, in his book, mentions this system was in use in the Vedic period. A day with 30 parts, counting is a sidereal day?

There is mention of kala and kastha in the Narayan Upanishad as a unit of time, however, there is no reference to their interrelationship as a unit of time during the Vedic period.

Though these units were used in the later period as subdivisionsof Muhurta.

The familiar words "Ghatika and Pala" as a division of the day are not mentioned in the Vedic/Pre-Siddhantic period. These were introduced during the post-Siddhantic period.

Some other astronomical references during this period are

Eclipses

The world witnessed a total solar eclipse on 08 April 2024 in the USA. It did create a lot of curiosity and awe about the celestial event. Also, a few precautionary directives were issued in the backdrop of the Solar eclipse. But does an occurrence of an eclipse create disturbances on Earth? There are coincidences, which confirm these speculations.

Rk Samhita describes the Solar eclipse as 

यत्वा सूयं स्वर्भानुस्तमसाविष्यदासुरः ॥ अक्षेत्रविद्य थामुग्धो भुवनान्यदीधयुः ॥ ५॥

स्वर्भानोरधयौंदद्र मायाऽअवो दिवो वत्तं माना अवाहन्‌ ॥ गृल्‌हं सूयं तमसापव्रतेन तुरीयंण ब्रह्मणाऽ विंददच्निः ।। ६॥, 

मामामिमं तव संतमन्र इरस्या दरुग्धो भियसा निगारित्‌ ।! | त्वं मित्रो असि सत्यराधास्ती मेहावतं वरुणस्च राजा ॥ ७॥

ग्राव्णो ह्या युयुजानः सपयंन्‌ कोरिणा देवान्नमसोपशिक्षन्‌ ।। अत्रिः सुयस्य दिवि चक्षुराधात. स्वभःनोरपमाथा श्रघक्षत्‌ ॥ ८ ॥

यं वं सूयं स्वर्भानुस्तमसा विंध्य दासुरः । अत्रयस्तमन्व विंदब्रह्यऽन्ये अक्क्रवन ॥ ९  |

                                                                         ऋ. स. ५. ४९

Description of these 5 verses can be summarised as 

" Oh! God Sun, when Rahu engulfs you with darkness Lord Indra will destroy 'Sarvabhanu'(Rahu). Sage Atri can protect us by dispelling the illusions of Rahu and get Sun free of darkness, sage Atri is the only one who can do this"

This description of eclipse highlights that,

1. The description does not show any apprehension or panic. That means eclipses were a normal celestial event.

2. Sage Atri, alone knew, when the eclipse would begin and end

3. In one expression ' Rahu may nor devour the Sun', but engulfed with darkness. It appears, that, Rahu and darkness are two different aspects. The notion that Rahu/Sarvabhanu devours the Sun would have come at a later date.

4. Vedic people were aware of the eclipses and a few had the knowledge of its prediction.

Planets

Many references are found in the Vedic texts mentioning, the Sun, Moon, Rahu and Ketu ( though Rahu and Ketu are not planets) that leave 5 planets in the visible zodiac. Though there are no specific mentions of these planets. However one can infer that the mentions are, regarding these  5 planets. Like,

अमी ये पंचोक्षणो मध्यं तस्थुमंहो दिवः ॥ 

देवत्रा नु प्रवाच्यं सध्रीचीना नि वावुर्तुवत्तं मे अस्य रोदसी ॥

                                                                       ऋ. स. १. १०५. १०.

"These mighty five are seen in the middle of the vast expanse of the sky. Even though they are seen coming together when I compose hymns in honour of gods, they have all gone away today...."

It is rare to witness all the 5 planets together at the same time. 

However, they were visible from 17-27 April 2022.

Many inferences can be drawn from the above verse. The original Vedic gods are none other than the wonders of nature and those luminous objects in the sky. Nirukta explains the root meaning of the word 'Deva'

is to shine, today we understand this meaning as 'God'. Therefore each planet does represent one god. There are numerous legends, in all cultures, describing the planets, constellations, and celestial objects, with a godly status. Nakshatras are also called the abode of gods, meaning the planets are found amongst the nakshatras.

'Panchdeva' is also mentioned, but it refers to planets rather than gods. We know there are 33 gods,( 12 Aditiyas, 11 Rudras,8 Vasus, Indra and Prajapati). Therefore, this statement regarding the five planets,  confirms that Vedic people had knowledge of planets.

The concept of Ashwin's as gods could have emerged from the two luminaries, Venus and Jupiter, and Ashwinhood was conferred on them When both the planets were seen together. This conjunction is not rare but is not frequent either. Since Venus is always close to the Sun, Jupiter wandes in the sky. The verse from Rk Samhita 5.73.3 explains as 

ईर्मान्यद पुषे वपुर्चक्रं रथस्य येमथुः । पयंन्या नाहुषा युगा मह्भा रर्जासि दीयथः ॥

                                                                            ऋ. सं. ५. ७३. ३.

'Oh, Ashwins! you have kept one luminous wheel of your chariot near the Sun for adorning him and you revolve around the world by the second wheel"

The story clearly indicates the movement of Venus and Jupiter.

Jupiter

There are two verses which give out the discovery of Jupiter 

बहस्पतिः प्रथम जायमानो महो ज्योतिषः परमे व्योमन्‌ ॥ ऋ. सं ४. ५०. ४. अथ. सं २० . ४.

 

" Jupiter was first born in the highest heaven of the shining light"

बहस्पतिः प्रथमं जायमानः॥ तिष्य नक्षत्रमभिसंबभूव ॥  ` ते. ब्रा. ३. १. १.

" Jupiter when born was first visible near the star Tishya(Pushya/

γ,δ,θ Cancri)"

Jupiter can form close conjunction with only 6 nakshatras { Pushya, Magha(Regulus), Vishakha (α,β,γ & ι Librae), Anuradha(β,δ,π, Scorpionis), Shatabhisha (Gama Aquarii), Revati(Zeta Piscium)} and the closest conjunction is with Tishya/ Pushya. 

This is because the maximum latitude of Jupiter is 1 degree 30'.

 Since the ruling deity of Pushya is Jupiter, this conjunction is still considered auspicious. (Guru Pushya Yog). 

Venus

Known as the morning or the evening star. It is one of the luminaries, which has incited many into poetry and prose, an awe-inspiring sight, even for the Vedic people, as mentioned in Rk Samhita 10.123

प्रय वेनश्चोदयत्पुदिनगर्भा ज्योतिजंराय्‌ रजसोविमाने ||                 ऋ.सं. १०. १२३. 

This hymn, " this Vena has risen...." is sung in honour of the deity 'Vena', referring to as a bright celestial object. There is also a mention of Shukra(Venus) as a shining object. Vena and Venus are the same.

Shukra is called Venus in Latin, Kupros in Greek, also known as 'Kupris', a female deity. Thus Vena/Venus, Kupris or cypris are all equivalent and may resemble Vena(h) and Shukra.

It infers that the Vedic people had sufficient knowledge of the 5 planets. 

Meteors and Comets

Comets, known as dhumketu, in all Indian languages, is mentioned in several places in the Vedic literature, RV and AV. Its literal meaning is 'smoke or dust banner'.

The Atharvaṇa Veda has a famous hymn in which dhūmaketu is mentioned along with the sun, moon and rāhu, indicating that in Vedic parlance too the word Ketu should have primarily referred to a visible celestial object. Is it a description of a comet being visible during an eclipse? Similar to the one on 08 April 2024 (Comet 12P-Pons-Brooks) was orbiting the Sun during the eclipse.

Maruts are well-known Vedic deities, taken to represent winds and thunderstorms inducing rain by traditionalists and modern scholars. However, their explicit relation with dhūmaketu provides a clue to their correct decipherment as meteoritic storms. Maruts are a

group of deities, usually known as the sons of Rudra and occasionally directly as Rudrāḥ.

A striking verse from Taittriya Brahman 3.9.22 says

एकं वा एतह्‌ वानामहः ।! यत्संवत्सरः . ते त्रा. ३. ६. २२.

"The year is equivalent to a day of gods"

The notion is that the gods dwell in the  Meru mountains at the north pole. We know, in the polar regions the day lasts for six months and the night for six months. Is it that this knowledge was available to the Vedic people? Yuga measure talks of  1 year of Earth equal to one day of Brahma.

........to be continued with Nakshatra नक्षत्र

___________________________________________

References

1. SB Dixit " Bhartiya Jyoti's Shastra" Part 1

2. William Brennand " Hindu Astronomy"

3. Ancient Indian Astronomy by RN Iyengar.

4. Ancient Astronomy by Prof TS Kuppanna Shastry

5. Paper on 'Vedang Jyotish of Lagdha' by KV Sarma

Vedic Period-2

  Astronomy During the Vedic Period-2

Time Units

KALPA and YUGA are common terms and, are understood as some unit of time denoting a specific period. However, KALPA is not used as a unit of time in Vedas, though it is used extensively during the post-Vedic period.

YUGA as a unit of time, finds a mention in the Vedas in several places. These references in the Vedas suggest that the word yuga does denote a certain period of time. This period is not quantified but is a smaller period of  5 to 10 years.  For example as given in the following verses

 युगे ुगे विदध्यं मृणद्भ्योगनेरथि यशसं धेहि नव्यसीं ॥ 

                                                                   | ऋ. स. ६. द. ५.

"Oh! God of fire, give riches and success to us who offer new words of praise to thee for the  sake of sacrifices in each yuga"__ Rk Samhita

था ओषधीः पूर्वां जाता देवेभ्यस्त्रयुगं पुरा ।

                                      ऋ. सं, १०. 8७. १.

"The herbs created by Gods in three yugas before" ----Rk Samhita. The Scholars have interpreted " Triyuga" as three yugas Kreta, Treta and Dwapar or three seasons Vasant, Varsha and Sharad.

All these references show yuga is used to denote some period, after which the event repeats itself. A periodic nature of time after which a phenomenon recurs, like an eclipse, planet rotations etc.

The word Yuga is used for 

 Emotional, Symbolic, calculation and calendric. Do, not confuse with Dwapar, Treta, Kali...of 432000 years as the duration of Yuga. These are used for calculation purposes.

In Vedang Jyotish, the yuga is taken to be a cycle of 5 years. The names of these years are संवत्सरः,परिवत्सरः,इदावत्सर:' अनुवत्सरः,इद्वत्सरः. These names occur in the Vedic texts but they do not occur in the Vedang Jyotish. There are many verses which mention these years in the ancient Vedic texts. it appears to be a system similar to the 5-year cycle of Vedang Jyotish. 

                    The months were Lunar and the Year was Solar

The caption appears odd, how can we have two different systems to count the same duration. However, this appears logical as most of the astronomical database was compiled by observation during the Vedic age.

It was natural in the Vedic age that the month was counted from the Moon. "Puranmasi", which we understand as the full Moon literally means the tithi on which the month ends. MASA a synonym for Moon was adopted as a time unit for months.

Numerous verses describe the year, having  12 months (13th month as intercalary for adjustment),360 days. The description is, both direct and indirect,for example

्रीणिच वशतानि षष्टिर संव॑त्सरस्याहानि.--सप्त च वं रतानि विंशतिश्च संवत्सरस्थाहोरात्रयेः `                                                             ए. ब्राः ७. १७.

"A year has 360 days , a year has 720 days ans nights together"

 Taitareya Brahman 3.8.3 describes the year and intercalary month, metaphorically as under

दा दशारत्नी रहना कतेव्यए २ च्रथोदशारत्नी देरिति ॥ ऋषभो वा एष ऋतूनां ॥ यत्संवत्सरः ।। तस्य त्रयोदशो मासो विष्टपं ।

॥ ऋषभ एष यज्ञानां ।॥

। यदहवमेधः॥ यथावा ऋवभस्व विष्टपं !! एवमतस्य विष्टपं ॥            ते. त्रा. ३.८. ३.

"Should the reigns in a horse sacrifice be 12 cubits in length or 13? The year of (six) seasons is a kind of bullock whose hunch is the 13th month. The horse sacrifice is the best of all sacrifices..."

The seasons are formed due to the Sun, therefore it was logical to assume that a year has elapsed when a particular season returns, hence the year counting was solar. Full moon to full Moon would then constitute a masa or a month. So the year was solar and the month Lunar.

To keep the seasons and the corresponding month synchronised with the actual environment, some adjustment was done  to match the Lunar month and the Solar year. The indirect reference to intercalary month points to the fact, that some methods were adopted for synchronisation.

As the months were Lunar, the year counting would also have been Lunar, but the Lunar year did not have 360 days, but less than that. However in practice a savan/solar year was in use and hence a mention of intercalary month adjustment, as mentioned above.

 However, In the Hijri calendar the month, say, Muharram, will pass through all seasons because the adjustment is carried out after 33 years (instead of 30-32 months).

There is no reference to any rule, stating how the intercalary month be adjusted during the Vedic age. However, Vedang Jyotish does give out the rules of adjustment in the later period.

Apart from the solar year, we have references to the Savana and Lunar years. There is no reference to Sidereal and Jovian years in the Vedas.

Days

 A Lunar month has only 29 1/2 days, not 30 days as is understood. So in two months, the total number of days is 59. This discrepancy of 1 day needs adjustment. 

A verse from Taittriya Samhita 7.5.6 says

                              षउहर्मासात्संपाचाहरत्सु्चंति             | त. सं. ७.५. ६.

" A day is omitted after some sadahas and masa are observed"

The reason for omitting the day is mentioned in Taittriya Brahaman 5.10.2

                                   यथा वे टतिराध्मात एवसंवसरोनुत्सुष्टः

" If a day is not omitted then the year will swell like bellows made of leather"

Interestingly in the Vedic period, One day of 24 hrs is called 'aha' अह: and a group of six such days are called sadahas and five sadahas make one masa (month) and several such sadahas and masas constituted to make 360 days of savanna year.

So a 6-day week and a 5-week month were prevalent during the Vedic period.

There is no mention of a 7-day week and the names of the 7 days of the week, during the Vedic period, as we know it today.

The only mention is of the 15th day as panchadashi पञ्चदशी. Other terms such as pratipada dwitiya etc may have been used to denote (day one, day two etc), day and nights (what we understand as Tithi), words like Shukla Chaturdashi, and Krishna Panchami have been found to denote the day of light and the dark half of the month.

As per, Taittriya Brahaman different names have been given for the days and nights in the light and dark half of the month. There are 15 names for day and 15 names for night.

 अह: is used to mention a day in a neuter gender form, whereas the word रात्रि, is feminine, hence the names of the nights are used in feminine gender. So ahoratra अहोरात्र is day and night. Hora होरा doesn't come from अहोरात्र.

Tithi

 We all are familiar with the word Tithi तिथि, meaning a day in Lunar month. However, during the Vedic  period, there is no mention of the word तिथि,(the way we understand it today)

                                       Length of the Day

The variable length of the day is due to the Sun.

The following lines in Rk Samhita 8.48.7 describe the phenomena. 

सोमराजन्‌ प्रण आयू'षि तारीरहानीव सूर्यो वासराणि ॥

                                                          ऋ. सं, ८. ४८. ७.

"Oh! Somraja! Increase the length of our lives, just as the sun increases the length of the day, which are dwellings of the world"

The Equinoctal Day

There are a lot of references to the equinox in the Vedas, during this period. The mentions are in the form of annual sacrifices, and that period mentioned relates to the equinox as an indirect meaning. But there is no explicit definition of equinox, on which the days and nights are equal.

........to be continued with parts of the Day.

_________________________________________

References

1. SB Dixit " Bhartiya Jyoti's Shastra" Part 1

2. William Brennand " Hindu Astronomy"

3. Coolebroke Essays.

4. Gen Alexander Cunningham "Book of Indian Eras"

5. Dr Nilesh Oak talks.