Astronomy

“Time creates the sky and the earth. Time creates that past and the future. By Time the sun burns, through Time all beings exist, in Time the eyes see. Time is the lord of all.”

This verse from the Atharva-veda (19.54) expresses the importance of time in Hindu culture. In India time is conceived as an unending flow that moves in great cycles. The Matsya Purana speaks of the waters of time. (See: Heinrisch Zimmer, Myths ans Symbols in Indian Art and Civilization Bollingen Series, Princeton University Press, p. 27) Sometimes those waters move in a peaceful way, sometime they move in great and chaotic torrents. So it is with time. The movements of the sun and the moon, and the other celestial bodies are the indication of this flow of time. The Bhagavata Purana describes how the passage of the sun across the atoms on this earth creates the reckoning of time. The record of time is the pancanga wherein the movements of these celestial bodies are precisely recorded. No religious festival, family event, or even a civic affair is performed without first consulting the pancanga to know the favorable movement of this flow of time.

The Sanskrit word “pancanga” is made of two parts: panca and anga. Pancameans five and anga means a limb or part. Thus the pancanga is a document made of five parts. These five parts are the tithi (lunar day), the vara (day of the week), the naksatra (lunar mansion), the yoga (luni-solar day) and the karana(half lunar day).

In order to understand these terms it is important to know how astronomers measure the sky. Just as a road map uses miles or kilometers to show distance between cities, so a celestial sky map uses degrees to show apparent distance between celestial objects. Keeping in mind that there are 360 degrees in a circle, it is easy to measure approximate degrees in the sky. Just raise your hand to the sky, and at arm’s length, use your hand to measure the degrees in the sky. See the accompaning illustration that shows how the hand can be used to measure degrees in the sky.

At arm’s length, for example, the width of the end of the little finger is almost one degree across. Check to see that the moon is about half a little finger in width and therefore can be estimated to be about a half a degree wide. This system is reasonably accurate for men, women and children, since people with smaller hands tend to have shorter arms. Astronomers have used this hand technique for thousands of years to make approximate measurements of the sky. To see how this system can be used to measure a common constellation see the illustration of the sapta-rsi (big dipper) and the star dhruva (polaris) to measure the degrees of separation.

As we begin to discuss the five elements of the Hindu almanac it is important to recognize the importance of the moon in Hindu culture. The basic calendar is primarily a lunar calendar. The lunar day, called a tithi, is all important in selecting a favorable time to begin a certain task. A person’s name is often derived from the lunar position in the heavens called a naksatra. The reason for this is simple. In Hindu astrology the moon rules the mind.

Tithi (Lunar Phase)

The first element of the Hindu pancanga is the tithi or lunar phase. This is perhaps the single most important element of the pancanga. It is the building block for the lunar month. Simply stated a tithi is a measurement of 12 degrees of longitudinal separation between the sun and the moon. Another way to put it is to say that a tithi is the daily phase of the moon. For example, at new moon (amavasya) the sun and the moon are separated by zero degrees. We can say they overlap. As they begin to separate the first tithi begins when the sun and the moon have separated by 12 degrees. The moon is now a tiny almost imperceptable sliver. The second tithi begins when they are separated by 24 degrees. The sliver is slightly larger. The third tithi begins when they have separated by 36 degrees. The digit of the moon is new clearly visible. And so it goes until the sun and moon have separated by 180 degrees. This tithi is called full moon, purnima. These first 15 tithis or phases of the moon make up the waxing phases of the moon which in Sanskrit this is called the sukla-paksa. This is the bright side of the lunar month. After purnima, full moon, the tithibegins again counting from one as the longitudanal separation between the sun and the moon decreases back to zero. This is called the waning phase of the moon or in Sanskrit, the krsna-paksa or dark side of the lunar month. At certain times of the month when the sun and moon can both be seen in the sky at the same time you can estimate the tithi by using the hand method to measure the longitudinal separation between the sun and the moon.

The tithis are sequentially numbered from both the points of the new moon as well as the full moon. See the accompaning illustration. In this way, the sukla-paksa, begining with the new moon (amavasya), is followed by the first tithi, then the second tithi, the third tithi and so on up to the 14th tithi. There is no 15th tithi. Instead, this tithi is called full moon (purnima). After the full moon, the waning phase (krsna-paksa) again begins with the first tithi, the secondtithi, the third tithi and so on up to the fourteenth tithi followed by the full moon. Afterwards the cycle repeats itself. In this way thirty tithis make up a lunar month, which is known as a masa. Some parts of India begin the month from the full moon whereas other parts begin the month from the new moon. Today, the lunar calendar is still in use throughout the world for Hindu religious purposes.

One of the greatest points of confusion between Hindu festival dates and the modern solar calendar is that the solar day begins at midnight whereas the lunartithi can begin at anytime of the solar day. For practical purposes, however, thetithi that is current at sunrise is taken as the prevailing tithi for the day. This means that if a tithi begins just after sunrise and ends before the sunrise of the next day, it is eliminated.This is possible because the tithi can last between 19 to 26 hours due to the changing speed of the earth and moon in their obits. On average a tithi lasts for only 0.95 of a solar day. When this occurs a break in the numerical ordering of the days takes place. These factors cause a lot of confusion between the lunar Hindu calendar and the modern solar calendar.

From an astrological perspective the various tithis are considered either auspicious or inauspicious for different events. In general the sukla-paksa(bright side) is considered condusive to growth, increase and properity and would be selected for such occasions as weddings, moving into new homes or starting businesses, etc. The moon’s krsna-paksa (dark side) is considered less favorable. In addition the 8th and 14th tithis, amavasya, as well as the 1st tithiof the sukla-paksa are generally considered inuaspicious. There are of course exceptions to this rule, the most notable of which are the various post funerary rites (sraddhas) that prefer the lunar dark phases. See the article “Hindu Funeral Rites and Ancestor Worship.”

Vara (The Day of the Week)

The second element of the Hindu pancanga is the day, vara. In Sanskrit the days of the week are clearly named after seven major astrological influences:

Sunday, the sun, ravi-vara

Monday, the moon, soma–vara

Tuesday, Mars, mangala–vara

Wednesday, Mercury, budha–vara

Thursday, Jupiter, guru–vara

Friday, Venus sukra–vara

Saturday, Saturn, sani–vara

You can still see this astrological influence in the English names, Sunday, Monday and Saturday for the sun, the moon and Saturn respectively. If you examine the French and Spanish words for the days of the week you will see an even greater connection. Astrologically these days are named after these celestial bodies because the influence of that celestial body is said to be prominent on that day. For example, Tuesday, being ruled by Mars, the planet of war, would be a good date to enter into a battle, but not a good day to get married or move into a new home!

Naksatra (Lunar Mansion)

The third element of the pancanga is naksatra. The best way to understandnaksatra is to observe the moon some evening. Notice the moon’s position in relation to the background of stars. The next evening, at the same time and in the same location, again observe the moon’s position in relation to the background of stars. You will see that it has moved consideralably. Use the raised hand technique to estimate how many degrees the moon has moved. The moon has moved somewhere between 10 and 15 degrees. In fact the moon has moved 13 degrees and 20 minutes. The region of the sky that has been displaced by the moon’s eastward movement in one day is called a naksatra. In English this known as a lunar mansion. There are 27 such lunar mansions in the 360 degrees the moon travels in one lunar month ( 13.3 x 27 = ~360). In the Hindu Almanac each of these lunar mansions is named after a star or group of stars in each region of the sky.

The naksatra is very important in Hindu culture. At the time of birth a person’s horoscope is made and one of the most important items to be known is thenaksatra. Many elements of a person’s character is thought to be determined by the naksatra. (Remember that the moon stands for the mind in Hindu astrology.) In many regions of India a person’s name is based on the naksatra.Perhaps the first syllable of the name is derived from the naksatra. At the time of a puja or religious ceremony a priest will ask for the naksatra of the person performing the religious service so that it can be recited in the opening statement of the puja called a sankalpa. At the time of marriage considerations the naksatras of the both the bride and groom may be compared to check for pschological compatability.

The following is a list of the 27 naksatras along with their western astronomical designations. Note that in some cases it is difficult to determine exactly which western star name corresponds to the naksatras.

1. Asvini–alpha arietis (Hamal)

2. Bharani–41 arietis

3. Krttika–Pleiades

4. Rohini–alpha tauri (Aldebaran)

5. Mrgasirsa–lambda orionis (Bellatrix)

6. Ardra–alpha orionis (Betelgeuse)

7. Punarvasu–beta geminorum (Castor)

8. Pusya–delta canceri (area of M44 Beehive cluster)

9. Aslesa–alpha canceri (sometimes taken as the Hydra or Alphard)

10. Magha–alpha leonis (Regulus)

11. Purvaphalguni–delta leonis (lion’s hind)

12. Uttara-phalguni–beta leonis (Denebola)

13. Hasta–gamma or delta corvi (Corvus)

14. Citra–alpha virginis (Spica)

15. Svati–alpha bootis (Arcturus)

16. Visakha–alpha libra

17. Anuradha–delta scorpionis

18. Jyestha–alpha scorpionis (Antares)

19. Mula–lambda scorpionis (near the globular cluster Shaula)

20. Purvasadha–delta sagittarii

21. Uttarasadha–sigma sagittarii (teapot)

22. Sravana–alpha aquilae (Altair)

23. Dhanistha–alpha delphini (Delphinis)

24. Satabhisa–lambda aqurii (Fomalhaut)

25. Purva-bhadrapada–alpha pegasi (Markab)

26. Uttara-bhadrapada–gamma pegasi

27. Revati–delta piscium

(To this group of 27 naksatras, one more naksatra known as abhit is sometimes added. Abhit includes the region of Vega in the constelation of Lyra. This is not on the path of the sun (solar eclipic) as are the other naksatrasand so can be ignored.)

This system of 27 naksatra was the original Hindu way of dividing the 360 degrees of the solar ecliptic. The system of the twelve signs of the zodiac, in Sanskrit called rasi, was a later addition to Hindu astronomy.

Yoga (The Luni-solar Day)

The yoga (luni-solar day) is the period during which the combined longitudinal motion of the sun and moon amounts to 13 degrees and 20 minutes. Like thenaksatras there are 27 yogas.

Karana (Half Tithi)

The final aspect of the pancanga is karana which is calculated to be 6 degrees of longitudinal separation between the sun and moon. In other words thekarana is half a tihi. There are two karanas in each tithi. In total there are eleven karanas that rotate through the 30 tithis that make up the lunar month.

Both a karana and a yoga are similar to a tithi in the sense that they are all a measure of the relationship between the sun and moon. Recall that a tithi was 12 degrees of longitudinal separation between the sun and moon, the yoga is the combined longitudinal motion of the sun and the moon. Here the karana is half the tithi. In Hindu astrology the sun and the moon are both perceived to have a great effect on life, and their motions are precisely calculated.

In addition to these five part of the traditional Hindu calendar the follow other elements may be added.Masa (Month)

The Hindu year contains twelve lunar months named after the naksatra in which the moon is full:

Caitra (March – April) (citra–naksatra)

Vaisakha (April – May) (visakha–naksatra)

Jyaistha (May – June) (jyestha–naksatra)

Asadha (June – July) (purvasadha–naksatra)

Sravana (July – August) (sravana–naksatra)

Bhadrapada (August – September) (purva–bhadrapada–naksatra)

Asvina (September – October) (asvini–naksatra)

Karttika (October – November) (krttika–naksatra)

Margasirsa or Agrahayana (November – December) (mrgasirsa–naksatra)

Pausa (December – January) (pusya-naksatra)

Magha (January – February) (magha–naksatra) and

Phalguna (February – March) (phalguna–naksatra).

Different parts of India start the year during different months. In general the year begins either in the vernal month of Caitra or in the autumnal month of Karttika.

Rtu (Season)

Traditionally India has six seasons (rtu), each comprised of two months. The six seasons are:

Vasanta (spring, March to May)

Grisma (summer, May to July)

Varsa (rainy, July to September)

Sarad (autumn, September to November)

Hemanta (winter, November to January) and

Sisira (cool, January to March)

Another aspect of the lunar calendar is that its twelve months based on the lunar days (tithis) contain about 354 days. So just as every 4th year on the solar calendar must add an extra day to make up for the discrepancy in the earth’s orbit around the sun, so every 30 months the lunar calendar must add an extra month. This leap-month (adika-masa) is generally inserted after the months ofAsadha or Sravana and is called either a second Asadha or Sravana. Thus every second or third year contains 13 months. This of course contributes considerably to differences between the lunar and solar calendars. The consequences of these differences makes it hard to reconcile the dates from one calendar to the other without intricate calculations.

HIndu dates are usually given in the order: month, paksa and tithi, thus Caitra,sukla 7 means the seventh day from the new moon of the month of Caitra.