Ancient eclipse records in India
M N Vahia*1, Saurabh Singh$ and B V Subbarayappa@*Tata Institute of Fundamental Research, Mumbai, India (vahia@tifr.res.in)$ Indian Institute of Astrophys, Bangalore, India, (saurabh_singh@ismu.ac.in)@31 Padmanabha Residency, Gururaja Layout, Bangalore (bidare25@gmail.com)

Abstract
Records of eclipses in are scattered over copper plates, temple inscriptions and other documents.
Over the last several decades, the Government of India has had systematic plan of collecting thiscorpus under Corpus Indicanum and other regional repositories. We have analysed these records
and identified a total of 1250 eclipse records half of which are Solar and half are Lunar. Since Solar
eclipses are rare, we have focused our analysis on Solar eclipses. We have isolated eclipses recordedby 2 or more observers and find 114 eclipses which satisfy this criterion. We compare the data withthe reports from East Asia catalogued by Tanikawa et al. (2010). We find that while the ΔT
calculations agree as a general trend, there are some others which are significantly different. We
also list 9 eclipses reported by Hari (2003) based on records of a 15th Century Indian astronomer that
could have possible records in East Asia.

Introductions
Eclipses are considered inauspicious in India as in other parts of the world. It is a period during which
Sun and Moon are perceived to be in trouble. Rana, 2011 has summarised the myths related toeclipses in different parts of the world. In India, eclipses are periods when donations are said to havethe maximum impact. Hence extensive donations are made and recorded in copper plates, stoneetchings etc. We have studied these records and we present our results here. In the next section webriefly mention the myths related to eclipses in India. In section 3 we discuss the data collected by us.
In section 4 we report our analysis and conclusions.

Indian myths about eclipses
From the Rig Vedic period (~1200 BC) eclipses are believed to occur when a demon Swarbhanu tries
to eat the Sun or the moon (Rig Veda 5.40, 5-9; Subbarayappa and Sarma, 1985 p 196). Briefly, thestory appears as follows.
Gods and their antagonists, the Asuras desired to become immortal. To achieve this, theyneeded nectar from sea. To extract this nectar, they needed to churn the seas. Since neither of themhad the strength to achieve this, they worked together and extracted the nectar. When the nectarcame out, the Gods sent a beautiful woman – Mohini to distract the Asuras. But one Asurea, Rahu
realised what is going on. He took the form of a God and tried to get some of the nectar. Sun and theMoon realised what was happening and tried to stop him. Mohini cut off his head. But since he hadalready taken a few drops of the nectar he became immortal in 2 parts his head forming one partand the body the other part. The head is referred to Rahu and the body is called Ketu. The immortal
Rahu was angered by this and since then, he is forever trying to take revenge on the Sun and theMoon. In the original version solar eclipses occur when Rahu catches up with the Sun and Lunar
Eclipses occur when Ketu catches up with the Moon. In later versions Ketu becomes a comet and it isRahu alone that causes both the eclipses.

1Address for correspondence vahia@tifr.res.inWith the rise of mathematical astronomy in India by Aryabhata (~500 AD; Balachandra Rao andVenugopal, 2008), the term Rahu is used to refer to the point of intersection of the ascending nodeof the point of intersection between equator and the ecliptic and Ketu is the descending node. The
location of these points can be mathematically tracked and eclipses are predicted to occur when theSun and the Moon are both at Rahu or Ketu.
Rahu and Ketu are also called ‘dark planets’ since unlike other planets, they are invisible in thesky. Unlike other seven ‘planets’ (Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn), whichmove counter clockwise in the sky, Rahu and Ketu make clockwise.

Eclipse records in ancient India
Records in Copper plates, stone inscription etc.
Since eclipses are considered inauspicious, they are considered a good occasion to make donations
to the gods and the records of these donations are found all over the country. These are also listed
in publications of the Government of India. We have studies the reports of such records in Annual
Reports on Epigraphy of the Archaeological Survey of India; Epigraphia Carnataka; Inscriptions ofKaokatiya of Warangal; South Indian Inscriptions; and Karnataka University Epigraphic Series; EI,Epigraphia Indica. We found 1250 records between 400 AD and 1800 AD (see also, Vahia andSubbarayappa, 2011). They are in traditional dates and converted to Gregorian calendar as per
widely accepted method of Swamikannu Pillai. Out of these about 1200 records are confirmed byNASA records, (Espenak, 2011) subject to the assumption that there may be up to 1 bit error in therecording and that the year conversion is as done by us. In 13% the eclipse is not seen, in 18% it is ona slightly different day and there seems to have been a recording error. However, the records do notmention either the time of eclipse or the depth of the eclipse. We therefore assume that if an eclipse
is seen, it must me at the level of 50% or more2.
In order to ensure that we are analysing the best data, we have taken eclipses that are reported by 2or more observers. We find 114 such records. In some of these records the mismatch between
Indian records and NASA predictions are drastic (Vahia et al., 2013). However, in 21 cases, (figure 1)
it is possible to calculate ΔT directly and compare it with the data given in Tanikawa et al., (2010). Ascan be seen, the records are broadly in agreement.

Figure 1: ΔT calculations for Indian eclipses compared with the data from Tanikawa et al, 2010;.

2

During the conference Dr.Tanikawa pointed out that the assumption that an eclipse is visible only if it is 50%
or higher may be too restrictive and eclipses of even 20% have been recorded in other cultures.

In figure 2, we have given the detailed comparison with the ΔT values obtained by us over the entire
dataset compared with the values from other observations (Tanikawa et al., 2010). As can be seen,
while the general trend between the two data set is comparable, about 20% of the eclipses give ΔT
value much higher than that from other observations. This may be because we have assumed thatan eclipse of 50% or higher will be the only ones visible to unaided eyes.

Figure 2: Coparision of he Indian data with the international records.

Other data from India
Indian astronomer Parameswara of 15th Century has recorded several eclipses in detail. Nine ofthese eclipses are discussed in detail (Hari, 2003). These are:
1. On Kali 16,43,524 (9 Nov 1398), the gnomonic shadow at the commencement was elevenand the end (of the eclipse) occurred in the afternoon. In this case, the duration (of theeclipse) was more than nine nāḍikās and hence the Sun also had to be computed by experts
by the method of successive approximation.
2. On Kali day 16,47,156 (19 Oct 1408) as the eclipse ended, the Sun was setting with a quarternāḍi to go.
3. On Kali 16,48,722 (Feb 1, 1413) at the first contract, the Sun’s gnomonical shadow wastwenty-four.
4. On Kali 16,52,000 (23 Jan 1422) a clear solar eclipse was observed in the region of Nava. The
gnomonic shadow at the moment of contact at this eclipse has been stated by some to beforty, while others stated it as thirty-five, on individual (reckonings).
5. Solar eclipse was observed in Gokarṇa on Kali day 16,53,387 (10 Nov 1425); it was not,however, seen on the banks of the Nīlā river.
6. Kali 16,55,130 (19 Aug 1430) a solar eclipse was seen in Gokarna which was not observed at
the confluence of rive Nīlā and the sea. However a discoloration at the fringes of the solar
orb was suspected by some students (of astronomy) even here on the banks of Nīlā on theabove date.
7. On Kali 16,55,484 (8 Aug 1431), at the time of last contact, the gnomonic shadow of the Sunwas five and a half.
8. On Kali 16,55,662 (2 Feb 1432) on the banks of the Nīlā river the Sun was seen by keen
viewers slightly eclipsed. The gnomonic shadow at the first contract of this eclipse wasfifteen and at the last contact it was nine and a half. On this day, the eyes of those observing

the Sun’s orb were not hurt; it is therefore to be presumed that the heat then was muchsubdued.
Eclipses 1 to 4 and 6 are eclipses whose path passes through India and East Asia and therefore therecords of these eclipses must also exist in Japan and they need to be further investigated.

Discussions and conclusions.
In early Indian mythology, eclipses occur when the nemesis of the Gods – the Asuras, and inparticular Rahu threatens Sun or Moon. Hence any donations to the Gods in terms of acts of charity,
on the occasion of the eclipse will bear rich rewards. Hence large scale donations tend to occur at
eclipses and these are recorded. India therefore has an extensive, but highly scattered and unevenly
distributed record of observations of eclipses. However, in virw of the documentation process
undertaken by the Government of India over the last several decades, it is possible to collate thisdata. This has been done in Subbarayappa and Vahia. About 85% of these eclipses are completely
consistent with An comparison of this data with NASA simulations (Epenak, 2011) shows that about
18% of the eclipse records are slightly off, suggesting error by scribes while 13% of the eclipses are
not found in the NASA records. The rest 79% of the eclipses records match well with the NASA data.
We then calculate ΔT from these records and find that they are broadly in agreement with records
from East Asia (Tanikawa et all, 2010). However, there are also some major differences with Indianrecords reporting eclipses that should not have been visible in India at all (Vahia et al., 2013). These
need to be studied in detail.
References Balachandra Rao S and Venugopal P, 2008, Eclipses in Indian astronomy, Bhavan Gandhi Centreof Science and Human Values, Bangalore, India
 Espenak, F., 2011, NASA/GSFC, 2011; http://eclipse.gsfc.nasa.gov/ eclipse.html
 Hari Chandra, 2003, Eclipse observations of Parameswara, the 14-15 century astronomer ofKerala, Indian Journal of Histroy of Science, 38, 43 - 57
 Rana N C, 2011, Myths and Legends related to eclipses, Vigyan Prasar, New Delhi, India, ISBN no81-7480-006-9
 Subbarayappa B V and Sarma K V, 1985, Indian Astronomy: A Sourcebook, Nehru Centre,
Mumbai India.
 Subbarayappa B V and Vahia M N, 2014, Eclipse records in ancient India, Indian Council for
Historical Research, New Delhi, India, in print Tanikawa K, Yamamoto T and Soma M, 2010, Solar Eclipses in the first half of the Chunqiu
period, PASJ, 62, 797 – 809
 Vahia M N, Singh S, Seta A and Subbarayappa B V, 2013, Ancient eclipses and long-term drifts inthe Earth–Moon system 2013, Current Science, 105, 61 – 71
 Vahia M N and Subbarayappa B V, 2011, Proceedings of the fourth symposium on history ofAstronomy, ed. M Soma and K Tanikawa, National Astronomical Observatory of Japan, p 16-19