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Explanation - Zi Wei Dou Shu
Brief Explanation of Astrology and Tarot
Astrology and tarot are very similar to one another. Here are a few examples as to why you should learn about them.
To know what to expect from a best free tarot readings, you should know what a tarot reading is, and what a tarot reading is not. You should know what a reading can or cannot do for you. People seek tarot readings because they have stumble upon some problems or tests in life that they find difficult to overcome. At this stage they feel that they need some spiritual or divine help. That is the reason they seek the help of a tarot reader. The tarot reader will then take efforts to relieve the pain and distress by offering probable solutions on how to solve a problem, or how to avoid possible problems.
True tarot reader:
A true tarot reader is often endowed with extraordinary abilities that will surprise people. For example, they can foretell certain events with a high degree of accuracy. Or they can see that someone has some problems without being told about these problems. At times, they can even sense the death of the people they know. Tarot readers can't really give details why they can see or hear special visions or voices. They just naturally know how and it is not uncommon for this tarot reading ability to be passed down from generation to generation.
It would be nice if you were able to spot a free tarot reader with the above said characteristics. Best free tarot readings should be able to gain an insight to the problems you are having without being told. Tarot reader should be able to suggest precious suggestion on how to overcome these problems. So best free tarot readings is meant to offer information about the truth. The information on some future events are not destiny, so do not give much weightage. While taking advice from free tarot reader expect honest information and insights into your problems in life. But in no way expect the pious and sacred psychic to solve everything for you. As human beings we all have problems and sufferings in life. Seek the advice from a tarot reader, and gather the courage to overcome the problems.
A psychic occurrence is an event or an example where the knowledge was of a type that could not be explained by the definite rules of the existing sciences. Tarot readings refer to a person or their aptitude and skill to distinguish things or experiences that are concealed from the normal senses. Best free tarot readings have a hold over popular imagination ever since time immemorial. They used to come in the attire of seers and prophets in the past. The most broadly identified method of fortune telling at this time was astrology. There were also some prophets or forecasters who could have direct apprehensions of the future. Down the line the part of the tarot reader and their position in the society has changed. There are many best free tarot readings with high vibrational levels who can guide you with information about your future and help you achieve your goals. Tarot reader should be honest and sincere that you can trust and use their information as guidance.
According to the Chinese system of astrology, there are rules based on which classifications are made.
The year of the birth, for instance, does not merely indicate the age of a person in the Chinese astrology but determines the phase of time to which the individual belongs.
These phases are demarcated again with the help of the guidelines and rules of astrology on which the Chinese system is based. The phase belongs to a sixty year old cycle of time.
The years, in the Chinese system of astrology are classified through three systems that exist.
They are- the heavenly stems,
the twelve earthly branches and
the twelve animals.
These systems of classifying years are so old that it is not possible to trace back the exact origin of these. They have been passed down the generations as traditions are. There are stories and folklore that exist, but there is no recorded evidence of when exactly these systems were formed except that they are from somewhere in the 2nd century BC; or for that matter, how they were formed. So far, it is only known that Chinese astrology is based on the traditional astronomy and calendars. It differs from the other systems of astrology in that it does employ the calculations depending upon the positions of the celestial bodies (the sun, the moon and the other planets) as the other systems do. Instead, the methodology can be related to the Chinese philosophy, which includes the theory of three harmony, heaven, earth, and water. Chinese philosophy also includes various principles such as the wu xing teachings, the theory of yin and yang, astronomy and the five planet system. Apart from this, there are the ten celestial stems, the earthly branches, and the lunisolar calendar.
In Chinese astrology, the five planet system included
Venus, symbol for Metal;
Jupiter, symbol for wood;
Mercury, symbol for water;
Mars, symbol for fire; and
Saturn, symbol for earth.
Therefore, according to the Chinese system of astrology, the destiny or the fate of an individual can be determined with the help of these.
There is a method known as the Zi Wei Dou Shu, In this, the fate of the individual is determined through one’s date of birth, season of birth, and hours of the birth. It is a highly elaborate method, and is used even today in the Chinese astrology in order to compute one’s fortune.
The zodiac of twelve animal signs is meant to represent twelve different types of personality. The Chinese Zodiac begins in the
Rat sign, moving on to the
Ox,
Tiger,
Rabbit,
Dragon,
Snake,
Horse Ram,
Monkey,
Rooster,
Dog and ending with
Pig.
These signs, as against the common misconception are assigned not only by the year, but also by the month, the day and the hours of a day. The combination of these gives an exact result. The Chinese system of astrology also differs a lot from the western science of astrology and the other South East Asian, the Hindu system and study of astrology.
Astrology and tarot are very similar to one another. Here are a few examples as to why you should learn about them.
To know what to expect from a best free tarot readings, you should know what a tarot reading is, and what a tarot reading is not. You should know what a reading can or cannot do for you. People seek tarot readings because they have stumble upon some problems or tests in life that they find difficult to overcome. At this stage they feel that they need some spiritual or divine help. That is the reason they seek the help of a tarot reader. The tarot reader will then take efforts to relieve the pain and distress by offering probable solutions on how to solve a problem, or how to avoid possible problems.
True tarot reader:
A true tarot reader is often endowed with extraordinary abilities that will surprise people. For example, they can foretell certain events with a high degree of accuracy. Or they can see that someone has some problems without being told about these problems. At times, they can even sense the death of the people they know. Tarot readers can't really give details why they can see or hear special visions or voices. They just naturally know how and it is not uncommon for this tarot reading ability to be passed down from generation to generation.
It would be nice if you were able to spot a free tarot reader with the above said characteristics. Best free tarot readings should be able to gain an insight to the problems you are having without being told. Tarot reader should be able to suggest precious suggestion on how to overcome these problems. So best free tarot readings is meant to offer information about the truth. The information on some future events are not destiny, so do not give much weightage. While taking advice from free tarot reader expect honest information and insights into your problems in life. But in no way expect the pious and sacred psychic to solve everything for you. As human beings we all have problems and sufferings in life. Seek the advice from a tarot reader, and gather the courage to overcome the problems.
A psychic occurrence is an event or an example where the knowledge was of a type that could not be explained by the definite rules of the existing sciences. Tarot readings refer to a person or their aptitude and skill to distinguish things or experiences that are concealed from the normal senses. Best free tarot readings have a hold over popular imagination ever since time immemorial. They used to come in the attire of seers and prophets in the past. The most broadly identified method of fortune telling at this time was astrology. There were also some prophets or forecasters who could have direct apprehensions of the future. Down the line the part of the tarot reader and their position in the society has changed. There are many best free tarot readings with high vibrational levels who can guide you with information about your future and help you achieve your goals. Tarot reader should be honest and sincere that you can trust and use their information as guidance.
According to the Chinese system of astrology, there are rules based on which classifications are made.
The year of the birth, for instance, does not merely indicate the age of a person in the Chinese astrology but determines the phase of time to which the individual belongs.
These phases are demarcated again with the help of the guidelines and rules of astrology on which the Chinese system is based. The phase belongs to a sixty year old cycle of time.
The years, in the Chinese system of astrology are classified through three systems that exist.
They are- the heavenly stems,
the twelve earthly branches and
the twelve animals.
These systems of classifying years are so old that it is not possible to trace back the exact origin of these. They have been passed down the generations as traditions are. There are stories and folklore that exist, but there is no recorded evidence of when exactly these systems were formed except that they are from somewhere in the 2nd century BC; or for that matter, how they were formed. So far, it is only known that Chinese astrology is based on the traditional astronomy and calendars. It differs from the other systems of astrology in that it does employ the calculations depending upon the positions of the celestial bodies (the sun, the moon and the other planets) as the other systems do. Instead, the methodology can be related to the Chinese philosophy, which includes the theory of three harmony, heaven, earth, and water. Chinese philosophy also includes various principles such as the wu xing teachings, the theory of yin and yang, astronomy and the five planet system. Apart from this, there are the ten celestial stems, the earthly branches, and the lunisolar calendar.
In Chinese astrology, the five planet system included
Venus, symbol for Metal;
Jupiter, symbol for wood;
Mercury, symbol for water;
Mars, symbol for fire; and
Saturn, symbol for earth.
Therefore, according to the Chinese system of astrology, the destiny or the fate of an individual can be determined with the help of these.
There is a method known as the Zi Wei Dou Shu, In this, the fate of the individual is determined through one’s date of birth, season of birth, and hours of the birth. It is a highly elaborate method, and is used even today in the Chinese astrology in order to compute one’s fortune.
The zodiac of twelve animal signs is meant to represent twelve different types of personality. The Chinese Zodiac begins in the
Rat sign, moving on to the
Ox,
Tiger,
Rabbit,
Dragon,
Snake,
Horse Ram,
Monkey,
Rooster,
Dog and ending with
Pig.
These signs, as against the common misconception are assigned not only by the year, but also by the month, the day and the hours of a day. The combination of these gives an exact result. The Chinese system of astrology also differs a lot from the western science of astrology and the other South East Asian, the Hindu system and study of astrology.
Transits of Venus
Ancient Greek, Egyptian, Babylonian, and Chinese observers knew of Venus and recorded the planet’s motions. The early Greeks thought that the evening and morning appearances of Venus represented two different objects, Hesperus - the evening star and Phosphorus - the morning star.[7] Pythagoras is credited with realizing they were the same planet. In the 4th century BC, Heraclides Ponticus proposed that both Venus and Mercury orbited the Sun rather than Earth. There is no evidence that any of these cultures knew of the transits.[8] Venus was important to ancient American civilizations, in particular for the Maya, who called it Noh Ek, "the Great Star" or Xux Ek, "the Wasp Star";[9] they embodied Venus in the form of the god Kukulkán (also known or related to Gukumatz and Quetzalcoatl in other parts of Mexico). In the Dresden Codex, the Maya charted Venus' full cycle, but despite their precise knowledge of its course, there is no mention of the transit.[10]
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, obscuring a small portion of the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2004 lasted six hours). A transit is similar to a solar eclipse by the Moon, but, although the diameter of Venus is almost 4 times that of the Moon, Venus appears smaller because it is much farther away from Earth. Before the space age, observations of transits of Venus helped scientists use the parallax method to calculate the distance between the Sun and the Earth.
Transits of Venus are among the rarest of predictable astronomical phenomena and currently occur in a pattern that repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. The periodicity is a reflection of the fact that the orbital periods of Earth and Venus are close to 8:13 and 243:395 resonances. Before 2004, the last pair of transits were in December 1874 and December 1882. The first of a pair of transits of Venus in the beginning of the 21st century took place on 8 June 2004 (see Transit of Venus, 2004) and the next will be on 6 June 2012 (see Transit of Venus, 2012). After 2012, the next transits of Venus will be in December 2117 and December 2125.[dead link][1]
A transit of Venus can be safely observed by taking the same precautions used when observing the partial phases of a solar eclipse. Staring at the brilliant disk of the Sun (the photosphere) with the unprotected eye can quickly cause serious and often permanent eye damage.[2]
Changes in global temperature and CO2 content.
Ice cores and deep sea bed cores provide the best available record of changes in global temperature and CO2 content of the atmosphere going back 800,000 years. The data shows a clear periodicity in global temperatures which is thought to be linked to the Milankovitch cycle.
Back in 1920, Milutin Milankovitch, a Serbian mathematician, proposed that fine changes in Earth’s orbit around the Sun could explain an approximately 100,000 year cycle in glaciation seen from geological evidence. The tilt of the Earth’s axis swings slightly over a 41,000 year cycle – the eccentricity of Earth’s orbit moves from almost circular to more elliptical and back again over a 413,000 year cycle – and overlaying that you have not only the precession of the equinoxes, which is an inherent wobble in the Earth’s axial spin over a 26,000 year cycle, but also a precession of the whole of Earth’s orbit over a 23,000 year cycle.
Ice core data does show a rough concordance between glaciation and the synchronicity of these orbital cycles. Even though there’s no significant change in the mean amount of solar radiation reaching the Earth over the period of its annual orbit – the orbital changes can lead to increased polar shadowing and cooling.
Once ice does start advancing from the poles, a positive feedback loop can develop – since more ice increases the albedo of Earth’s surface and reflects more of the Sun’s heat back into space, thus reducing mean global temperatures.
It’s thought that what limits the ice advancing is increasing CO2 in the atmosphere – which can be measured from trapped bubbles of air in the ice cores. More ice formation leads to less exposed land area for photosynthesis and silicate rock weathering to remove CO2 from the atmosphere. So the more ice that’s formed, the more CO2 accumulates in the atmosphere – which causes mean global temperatures to rise, which limits ongoing ice formation.
Of course the opposite is true in an ice-melting phase. Ice melting also follows a positive feedback loop since less ice means less albedo, meaning less solar radiation is reflected back into space and mean global temperatures rise. But again, CO2 becomes the limiting factor. With more exposed land, more CO2 is drawn from the atmosphere by photosynthesizing forests and rock weathering. A consequent drop in atmospheric CO2 cools the planet and hence limits ongoing ice melting.
But there lies the rub. We are in an ice-melting phase of the Milankovitch cycle now, where the Earth’s orbit is closer to circular and the Earth’s tilt is closer to perpendicular. But CO2 levels aren’t declining – partly because we’ve chopped a lot of trees and forests down, but mostly because of anthropogenic CO2 production. Without the limiting factor of declining CO2 we’ve seen in previous Milankovitch cycles, presumably the ice is just going to keep on melting as the albedo of the Earth surface declines.
Vedic Zodiac
Some scholars have claimed that the Babylonians invented the zodiac of 360 degrees around 700 BCE, perhaps even earlier. Many claim that India received the knowledge of the zodiac from Babylonia or even later from Greece. However, as old as the Rig Veda, the oldest Vedic text, there are clear references to a chakra or wheel of 360 spokes placed in the sky. The number 360 and its related numbers like 12, 24, 36, 48, 60, 72, 108, 432 and 720 occur commonly in Vedic symbolism. It is in the hymns of the great Rishi Dirghatamas (RV I.140 - 164) that we have the clearest such references.
Dirghatamas is one of the most famous Rig Vedic Rishis. He was the reputed purohit or chief priest of King Bharata (Aitareya Brahmana VIII.23), one of the earliest kings of the land, from which India as Bharata (the traditional name of the country) was named.
Dirghatamas was one of the Angirasa Rishis, the oldest of the Rishi families, and regarded as brother to the Rishi Bharadvaja, who is the seer of the sixth book of the Rig Veda. Dirghatamas is also the chief predecessor of the Gotama family of Rishis that includes Kakshivan, Gotama, Nodhas and Vamadeva (seer of the fourth book of the Rig Veda), who along with Dirghatamas account for almost 150 of the 1000 hymns of the Rig Veda. His own verses occur frequently in many Vedic texts, a few even in the Upanishads.
The hymns of Dirghatamas speak clearly of a zodiac of 360 degrees, divided in various ways, including by three, six and twelve, as well as related numbers of five and seven. We must remember that the zodiac is first of all a mathematical division of the heavens such as this hymn outlines. This is defined mainly according to the elements, qualities and planetary rulerships of the twelve signs. The symbols we ascribe to these twelve divisions is a different factor that can vary to some degree. The actual stars making up the constellation that goes along with the sign is yet a third factor. For example, some constellations are less or more than thirty degrees, but the mathematical or harmonic division of each sign will only be thirty degrees. What is important about the hymns of Dirghatamas is that he shows the mathematical basis of such harmonic divisions of a zodiac of 360 degrees.
For Dirghatamas, as was the case for much of later Vedic astronomy, the main God of the zodiac is Vishnu. Vishnu rules over the highest heaven and is sometimes identified with the pole star or polar point, which in the unique view of Vedic astronomy is the central point that governs all celestial motions and form which these are calculated.
According to Dirghatamas Rig Veda I.155.6, "With four times ninety names (caturbhih sakam navatim ca namabhih), he (Vishnu) sets in motion moving forces like a turning wheel (cakra)." This suggests that even in Vedic times Vishnu had 360 names or forms, one for each degree of the zodiac. A fourfold division may correspond to the solstices and equinoxes. Elsewhere Dirghatamas states, I.164.36, "Seven half embryos form the seed of the world. They stand in the dharma by the direction of Vishnu." This probably refers to the seven planets.
Most of the astronomical information occurs in his famous Asya Vamasya Hymn I.164. Much of this hymn can be understood as a description of the zodiac. It begins:
1. Of this adorable old invoker (the Sun) is a middle brother who is pervasive (the Wind or lightning). He has a third brother, whose back carries ghee (Fire). There I saw the Lord of the people (the Sun) who has seven children.
This verse is referring to the usual threefold Vedic division of Gods and worlds as the Fire (Agni) on Earth, the Wind or Lightning (Vayu) in the Atmosphere and the Sun (Surya) in Heaven. This also may refer to the three steps or strides of Vishnu through which he measures the Earth, the Atmosphere and Heaven. The Sun is also a symbol of the supreme light or the supreme Sun God that is Vishnu. The Sun or supreme light has seven children, the visible Sun, Moon and five planets.
We should note that the zodiac of twelve signs is divided into three sections based upon a similar understanding, starting with Aries or fire (cardinal fire ruled by Mars, who in Vedic thought is the fire born of the Earth), then with Leo or the Sun (fixed fire ruled by the Sun), and then with Sagittarius, the atmospheric fire, lightning or wind (mutable fire ruled by Jupiter, the God of the rains).
2. Seven yoke the chariot that has a single wheel (chakra). One horse that has seven names carries it. The wheel has three naves, is undecaying and never overcome, where all these beings are placed.
The zodiac is the single wheeled-chariot or circle yoked by the seven planets which are all forms of the Sun or sunlight. It is the wheel of time on which all beings are placed. The Vedic horse (ashva) is symbolic of energy or propulsive force.
3. This chariot which the seven have mounted has seven wheels (chakras) and is carried by seven horses. The seven sisters sing forth together, where are hidden the seven names of the cows.
The seven planets create their seven rotations or seven wheels. Each has its horse, its energy or velocity. Each has its feminine power or sister, its power of expression. It carries its own hidden name or secret knowledge (symbolically cows or rays). This refers to the astrological influences of the planets.
11. The wheel of law with twelve spokes does not decay as it revolves around heaven. Oh Fire, here your 720 sons abide.
The circle of the zodiac has twelve signs. It has 720 half degrees or twins, making 360 total. The Shatapatha Brahmana X.5.5, a late Vedic text, also speaks of a wheel of heaven with 720 divisions. "But indeed that Fire-altar is also the Nakshatras. For there are twenty seven of these Nakshatras and twenty-seven secondary Nakshatras. This makes 720." Twenty-seven times twenty-seven Nakshatras equals 729, with which some overlap can be related to the 720 half-degrees of the zodiac.
12. The Father with five feet and twelve forms, they say, dwells in the higher half of heaven full of waters. Others say that he is the clear-seeing one who dwells below in a sevenfold wheel that has six spokes.
The five feet of the father or the Sun are the five planets or the five elements that these often refer to (to which Vedic thought associates the five sense organs and five motor organs in the human body). His twelve forms are the twelve signs. The Sun in the higher half of heaven with the waters is the signs Leo with Cancer (ruled by the Moon), with the other five planets being the five feet, each ruling two signs. In Vedic thought, the Sun is the abode of the waters, which we can see in the zodiac by the proximity of the signs Cancer and Leo.
The sevenfold wheel is the zodiac moved by the seven planets. The six spokes are the six double signs through which the planets travel. The same verse occurs in the Prashna Upanishad I.11 as a symbol for the year.
13. Revolving on this five-spoked wheel all beings stand. Though it carries a heavy load, its axle does not over heat. From of old it does not break its ancient laws.
The five-spoked wheel is again the zodiac ruled by five planets and five elements and their various internal and external correspondences.
14. The undecaying wheel (circle) together with its felly (circumference), ten yoked to the upward extension carry it. The eye of the Sun moves encompassing the region. In it are placed all beings.
This may again refer to the ten signs ruled by the five planets, with each planet ruling two signs. The eye of the Sun may be the sign Leo through which the solar influence pervades the zodiac or just the Sun itself. The upward extension may be the polar region.
15. Of those that are born together, the seventh is born alone. The six are twins (yama), Divine born rishis. The wishes that they grant are apportioned according to their nature. Diversely made for their ordainer, they move in different forms.
The six born together or are twins are the twelve signs, two of which are ruled by one planet (considering the Sun and Moon as a single planetary influence). The seventh that is singly born is the single light that illumines all the planets. Elsewhere the Rig Veda X.64.3 speaks of the Sun and Moon as twins (yama) in heaven.
The planets are often associated with the rishis in Vedic thought, particularly the rishis Brihaspati (Jupiter), Shukra (Venus) and Kashyapa (the Sun) which became common names for the planets. Their ordainer or stabilizer may be the pole star (polar point).
48. Twelve are its fellies. The wheel is one. It has three naves. Who has understood it? It are held together like spokes the 3 60, both moving and non-moving.
This perhaps the clearest verse that refers to the zodiac of twelve signs and three hundred and sixty degrees. The same verse also occurs in Atharva Veda (X.8.4). The zodiac has three divisions as fire, lightning and Sun or Aries, Sagittarius and Leo that represent these three forms of fire. The 360 spokes are the 360 degrees which revolve in the sky but remain in the same place in the zodiac.
Yet another verse (43) of this same hymn of Dirghatamas refers to the Vishuvat, the solstice or equinox, showing that such astronomical meanings are clearly possible.
If we examine the hymn overall, we see that a heavenly circle of 360 degrees and 12 signs is known, along with 7 planets. It also has a threefold division of the signs which can be identified with that of fire, wind (lightning) and Sun (Aries, Sagittarius, Leo) and a sixfold division that can be identified with the planets each ruling two signs of the zodiac. This provides the basis for the main factors of the zodiac and signs as we have known them historically. We have all the main factors for the traditional signs of the zodiac except the names and symbols of each individual sign. This I will address in another article.
Elsewhere in Vedic literature is the idea that when the Creator created the stars he assigned each an animal of which there were originally five, the goat, sheep, cow, horse and man (Shatapatha Brahmana X.2.1). This shows a Vedic tradition of assigning animals to constellations. The animals mentioned are the man, goat, ram, bull and horse, which contain several of the zodiacal animals.
The zodiac in Vedic thought is the wheel of the Sun. It is the circle created by the Sun’s rays. The Shatapatha Brahmana X.5.4 notes, "But, indeed, the Fire-altar also is the Sun. The regions are its enclosing stones, and there are 360 of these, because 360 regions encircle the Sun on all sides. And 360 are the rays of the Sun."
The Zodiac and the Subtle Body
Clearly this hymn contains a vision of the zodiac but its purpose is not simply astronomical, nor is the zodiac the sole subject of its concern. Besides the outer zodiac of time and the stars there is the inner zodiac or the subtle body and its chakra system. The seven chakras mentioned are also the seven chakras of the subtle body. In Vedic thought the Sun that rules time outwardly corresponds inwardly to Prana, the spirit, soul or life-force (Maitrayani Upanishad VI.1). Prana is the inner Sun that creates time at a biological level through the process of breathing. It is also the energy that runs up and down the spine and flows through the seven chakras strung like lotuses along it.
According to Vedic thought (Shatapatha Brahmana XII.3.28) we have 10,800 breaths by day and by night or 21,600 a day. This corresponds to one breath every four seconds. The same text says that we have as many breaths in one muhurta (1/30 of a day or 48 minutes) as there are days and nights in the year or 720, so this connection of the outer light and our inner processes is quite detailed at an early period.
In Vedic thought the subtle body is composed of the five elements, the five sense organs and five motor organs, which correspond to different aspects of its five lower chakras .On top of these five are the mind and intellect (manas and buddhi) which are often compared to the Moon and the Sun and relate to the two higher chakras. They can be added to these other five factors, like the five planets, making seven in all. The chakras of Dirghatamas, though outwardly connected to the zodiac, are inwardly related to the subtle body, a connection that traditional commentators on the hymn like Sayana or Atmananda have noted.
This hymn of Dirghatamas contains many other important and cryptic verses on various spiritual matters that are connected to but go beyond the issues of the zodiac. It is written in the typical Vedic mantric and symbolic language to which it provides two keys;
39. The supreme syllable of the chant in the supreme ether, in which all the Gods reside, those who do not know this, what can they do with the Veda? Those who know it alone are gathered here.
45. Four are the levels of speech. Those trained in the knowledge, the wise know them all. Three hidden in secrecy cannot be do not stir. Mortals speak only with the fourth.
There is clearly a hidden knowledge behind these verses, which reflect an esoteric tradition of spiritual knowledge that was mainly accessible for initiates who had the keys to open its veils. We cannot simply take such verses superficially but must look deeply and see what they imply. Then the pattern of their inner meaning can come forth. If we do this, the astronomical and astrological side cannot be ignored.
Pingree’s Views
Western scholars of the history of astronomy like David Pingree have accepted the astronomical basis of this hymn. In an article, "Astronomy in India" in Astronomy Before the Telescope, C. Walker (ed.), St. Martin's Press, New York, 1996, pps. 123-124, Pingree suggests that Mul. Apin, Babylonian tablets that date from 687 to 500 BC has "’an ideal calendar' in which one year contains 12 months, each of which has 30 days, and consequently exactly 360 days; a late hymn of the Rgveda refers to the same ‘ideal calendar’. And Mul.Apin describes the oscillation of the rising-point of the sun along the eastern horizon between its extremities when it is at the solstices; the same oscillation is described in the Aitareya Brahmana.’" This ideal calendar is the basis for the zodiac and its twelve signs at a mathematical level. Clearly Pingree is referring to Rig Veda I.164 as his ‘late’ hymn of the Rig Veda.
To quote from David Pingree’s "History of mathematical astronomy in India," in the Dictionary of Scientific Biography, C.S. Gillespie (ed.), pp. 533-633, Charles Scribners, New York, 1981, page 534: "In the case of the priority of the Rgveda to the brahmanas, it is not always clear that the views expressed in the latter developed historically after the composition of the former. All texts that can reasonably be dated before ca. 500 BC are here considered to represent essentially a single body of more or less uniform material." The point of his statement is to try to get such Rig Veda references as those of Dirghatamas later than the Brahmana texts as both reflect a similar sophisticated astronomy, which is necessary to make it later than the Babylonian references and a product of a Babylonian influence as he proposes. This requires reducing all the layers of Vedic literature to a more or less uniform mass at a very late date, which is contrary to almost every view of the text.
Clearly this Rig Veda hymn, which has parallels and developments in the Brahmanas (like the Shatapatha Brahmana quoted in this chapter), must be earlier and show that such ideas were much older than the Brahmanas. To maintain his late date for Vedic astrology, Pingree must assume that this hymn or its particular astronomical verses were late interpolations to the Rig Veda, around 500 BCE or about the time of the Buddha. This is rather odd because the Buddha is generally regarded as having come long after the Vedic period, while the actual text is usually dated well before 1000 BCE (some have argued even to 3000 BCE).
Even the Brahmanas, like the Upanishads that come after them, are pre-Buddhist by all accounts. Perhaps the main Vedic ritual given in the Brahmanas, the Gavamayana, follows the model of a year of 360 days and is divided into two halves based upon the solstices, showing that such an ‘ideal’ calendar was central to Vedic thought. That such an ideal calendar has its counterpart in the sky is well reflected in Vedic ideas saying that equate the days and nights with the Sun’s rays and with the stars (as we have noted in Shatapatha Brahmana with 720 Upanakshatras)*. The Brahmanas, we should also note, emphasize the Krittikas or the Pleiades as the first of the Nakshatras, reflecting an astronomical era of the Taurus equinox. The Shatapatha Brahmana notes that the Krittikas mark the eastern direction.
In addition, the hymn, its verses and commentaries on them are found in many places in Vedic literature, along with support references to Nakshatras. It cannot be reduced to a late addition but is an integral part of the text.
That being the case, a zodiac of 360 degrees and its twelvefold division are much older in India than any Greek or even Babylonian references that he has come up with.
Pingree also tries to reduce the ancient Vedic calendar work Vedanga Jyotish to 500 BCE or to a Babylonian influence. However, the internal date of this late Vedic text is of a summer solstice in Aslesha or 1300 BCE, information referenced by Varaha Mihira in his Brihat Samhita (III.1-2). "There was indeed a time when the Sun’s southerly course (summer solstice) began from the middle of the Nakshatra Aslesha and the northerly one (winter solstice) from the beginning of the Nakshatra Dhanishta. For it has been stated so in ancient works. At present the southerly course of the Sun starts from the beginning of Cancer and the other from the initial point of the sign Capricorn." The middle of Aslesha is 23 20 Cancer, while the beginning of Dhanishta (Shravishta) is 23 20 Capricorn. Calculating the precession accordingly, this is obviously a date of around 1300 BCE.
There are yet earlier references in the Vedas like Atharva Veda XIX.6.2 that starts the Nakshatras with Krittika (the Pleiades) and places the summer solstice (ayana) in Magha (00 - 13 20 Leo), showing a date before 1900 BCE. These I have examined in detail in my book Gods, Sages and Kings (Lotus Press). Clearly the Vedas show the mathematics for an early date for the zodiac as well as the precessional points of these eras long before the Babylonians or the Greeks supposedly gave them the zodiac.
It is not surprising that India could have invented the zodiac and circle of 360 degrees. After all, the decimal system and the use of zero came from India. In this regard, as early as the Yajur Veda, we find names for numbers starting with one, ten, one hundred and one thousand ending with one followed by twelve zeros (Shukla Yajur Veda XVII.2).
The Rig Veda has another cryptic verse that suggests its cosmic numerology. According to it the Cosmic Bull has four horns, three feet, two heads and seven hands (Rig Veda IV.58.3). This sounds like a symbolic way of presenting the great kalpa number of 4,320,000,000 years. Such large numbers for the universe are typical to Indian thought, but scholars such as Pingree would also ascribe them to a Babylonian origin. However, the literature suggests the opposite.
Dirghatamas is one of the most famous Rig Vedic Rishis. He was the reputed purohit or chief priest of King Bharata (Aitareya Brahmana VIII.23), one of the earliest kings of the land, from which India as Bharata (the traditional name of the country) was named.
Dirghatamas was one of the Angirasa Rishis, the oldest of the Rishi families, and regarded as brother to the Rishi Bharadvaja, who is the seer of the sixth book of the Rig Veda. Dirghatamas is also the chief predecessor of the Gotama family of Rishis that includes Kakshivan, Gotama, Nodhas and Vamadeva (seer of the fourth book of the Rig Veda), who along with Dirghatamas account for almost 150 of the 1000 hymns of the Rig Veda. His own verses occur frequently in many Vedic texts, a few even in the Upanishads.
The hymns of Dirghatamas speak clearly of a zodiac of 360 degrees, divided in various ways, including by three, six and twelve, as well as related numbers of five and seven. We must remember that the zodiac is first of all a mathematical division of the heavens such as this hymn outlines. This is defined mainly according to the elements, qualities and planetary rulerships of the twelve signs. The symbols we ascribe to these twelve divisions is a different factor that can vary to some degree. The actual stars making up the constellation that goes along with the sign is yet a third factor. For example, some constellations are less or more than thirty degrees, but the mathematical or harmonic division of each sign will only be thirty degrees. What is important about the hymns of Dirghatamas is that he shows the mathematical basis of such harmonic divisions of a zodiac of 360 degrees.
For Dirghatamas, as was the case for much of later Vedic astronomy, the main God of the zodiac is Vishnu. Vishnu rules over the highest heaven and is sometimes identified with the pole star or polar point, which in the unique view of Vedic astronomy is the central point that governs all celestial motions and form which these are calculated.
According to Dirghatamas Rig Veda I.155.6, "With four times ninety names (caturbhih sakam navatim ca namabhih), he (Vishnu) sets in motion moving forces like a turning wheel (cakra)." This suggests that even in Vedic times Vishnu had 360 names or forms, one for each degree of the zodiac. A fourfold division may correspond to the solstices and equinoxes. Elsewhere Dirghatamas states, I.164.36, "Seven half embryos form the seed of the world. They stand in the dharma by the direction of Vishnu." This probably refers to the seven planets.
Most of the astronomical information occurs in his famous Asya Vamasya Hymn I.164. Much of this hymn can be understood as a description of the zodiac. It begins:
1. Of this adorable old invoker (the Sun) is a middle brother who is pervasive (the Wind or lightning). He has a third brother, whose back carries ghee (Fire). There I saw the Lord of the people (the Sun) who has seven children.
This verse is referring to the usual threefold Vedic division of Gods and worlds as the Fire (Agni) on Earth, the Wind or Lightning (Vayu) in the Atmosphere and the Sun (Surya) in Heaven. This also may refer to the three steps or strides of Vishnu through which he measures the Earth, the Atmosphere and Heaven. The Sun is also a symbol of the supreme light or the supreme Sun God that is Vishnu. The Sun or supreme light has seven children, the visible Sun, Moon and five planets.
We should note that the zodiac of twelve signs is divided into three sections based upon a similar understanding, starting with Aries or fire (cardinal fire ruled by Mars, who in Vedic thought is the fire born of the Earth), then with Leo or the Sun (fixed fire ruled by the Sun), and then with Sagittarius, the atmospheric fire, lightning or wind (mutable fire ruled by Jupiter, the God of the rains).
2. Seven yoke the chariot that has a single wheel (chakra). One horse that has seven names carries it. The wheel has three naves, is undecaying and never overcome, where all these beings are placed.
The zodiac is the single wheeled-chariot or circle yoked by the seven planets which are all forms of the Sun or sunlight. It is the wheel of time on which all beings are placed. The Vedic horse (ashva) is symbolic of energy or propulsive force.
3. This chariot which the seven have mounted has seven wheels (chakras) and is carried by seven horses. The seven sisters sing forth together, where are hidden the seven names of the cows.
The seven planets create their seven rotations or seven wheels. Each has its horse, its energy or velocity. Each has its feminine power or sister, its power of expression. It carries its own hidden name or secret knowledge (symbolically cows or rays). This refers to the astrological influences of the planets.
11. The wheel of law with twelve spokes does not decay as it revolves around heaven. Oh Fire, here your 720 sons abide.
The circle of the zodiac has twelve signs. It has 720 half degrees or twins, making 360 total. The Shatapatha Brahmana X.5.5, a late Vedic text, also speaks of a wheel of heaven with 720 divisions. "But indeed that Fire-altar is also the Nakshatras. For there are twenty seven of these Nakshatras and twenty-seven secondary Nakshatras. This makes 720." Twenty-seven times twenty-seven Nakshatras equals 729, with which some overlap can be related to the 720 half-degrees of the zodiac.
12. The Father with five feet and twelve forms, they say, dwells in the higher half of heaven full of waters. Others say that he is the clear-seeing one who dwells below in a sevenfold wheel that has six spokes.
The five feet of the father or the Sun are the five planets or the five elements that these often refer to (to which Vedic thought associates the five sense organs and five motor organs in the human body). His twelve forms are the twelve signs. The Sun in the higher half of heaven with the waters is the signs Leo with Cancer (ruled by the Moon), with the other five planets being the five feet, each ruling two signs. In Vedic thought, the Sun is the abode of the waters, which we can see in the zodiac by the proximity of the signs Cancer and Leo.
The sevenfold wheel is the zodiac moved by the seven planets. The six spokes are the six double signs through which the planets travel. The same verse occurs in the Prashna Upanishad I.11 as a symbol for the year.
13. Revolving on this five-spoked wheel all beings stand. Though it carries a heavy load, its axle does not over heat. From of old it does not break its ancient laws.
The five-spoked wheel is again the zodiac ruled by five planets and five elements and their various internal and external correspondences.
14. The undecaying wheel (circle) together with its felly (circumference), ten yoked to the upward extension carry it. The eye of the Sun moves encompassing the region. In it are placed all beings.
This may again refer to the ten signs ruled by the five planets, with each planet ruling two signs. The eye of the Sun may be the sign Leo through which the solar influence pervades the zodiac or just the Sun itself. The upward extension may be the polar region.
15. Of those that are born together, the seventh is born alone. The six are twins (yama), Divine born rishis. The wishes that they grant are apportioned according to their nature. Diversely made for their ordainer, they move in different forms.
The six born together or are twins are the twelve signs, two of which are ruled by one planet (considering the Sun and Moon as a single planetary influence). The seventh that is singly born is the single light that illumines all the planets. Elsewhere the Rig Veda X.64.3 speaks of the Sun and Moon as twins (yama) in heaven.
The planets are often associated with the rishis in Vedic thought, particularly the rishis Brihaspati (Jupiter), Shukra (Venus) and Kashyapa (the Sun) which became common names for the planets. Their ordainer or stabilizer may be the pole star (polar point).
48. Twelve are its fellies. The wheel is one. It has three naves. Who has understood it? It are held together like spokes the 3 60, both moving and non-moving.
This perhaps the clearest verse that refers to the zodiac of twelve signs and three hundred and sixty degrees. The same verse also occurs in Atharva Veda (X.8.4). The zodiac has three divisions as fire, lightning and Sun or Aries, Sagittarius and Leo that represent these three forms of fire. The 360 spokes are the 360 degrees which revolve in the sky but remain in the same place in the zodiac.
Yet another verse (43) of this same hymn of Dirghatamas refers to the Vishuvat, the solstice or equinox, showing that such astronomical meanings are clearly possible.
If we examine the hymn overall, we see that a heavenly circle of 360 degrees and 12 signs is known, along with 7 planets. It also has a threefold division of the signs which can be identified with that of fire, wind (lightning) and Sun (Aries, Sagittarius, Leo) and a sixfold division that can be identified with the planets each ruling two signs of the zodiac. This provides the basis for the main factors of the zodiac and signs as we have known them historically. We have all the main factors for the traditional signs of the zodiac except the names and symbols of each individual sign. This I will address in another article.
Elsewhere in Vedic literature is the idea that when the Creator created the stars he assigned each an animal of which there were originally five, the goat, sheep, cow, horse and man (Shatapatha Brahmana X.2.1). This shows a Vedic tradition of assigning animals to constellations. The animals mentioned are the man, goat, ram, bull and horse, which contain several of the zodiacal animals.
The zodiac in Vedic thought is the wheel of the Sun. It is the circle created by the Sun’s rays. The Shatapatha Brahmana X.5.4 notes, "But, indeed, the Fire-altar also is the Sun. The regions are its enclosing stones, and there are 360 of these, because 360 regions encircle the Sun on all sides. And 360 are the rays of the Sun."
The Zodiac and the Subtle Body
Clearly this hymn contains a vision of the zodiac but its purpose is not simply astronomical, nor is the zodiac the sole subject of its concern. Besides the outer zodiac of time and the stars there is the inner zodiac or the subtle body and its chakra system. The seven chakras mentioned are also the seven chakras of the subtle body. In Vedic thought the Sun that rules time outwardly corresponds inwardly to Prana, the spirit, soul or life-force (Maitrayani Upanishad VI.1). Prana is the inner Sun that creates time at a biological level through the process of breathing. It is also the energy that runs up and down the spine and flows through the seven chakras strung like lotuses along it.
According to Vedic thought (Shatapatha Brahmana XII.3.28) we have 10,800 breaths by day and by night or 21,600 a day. This corresponds to one breath every four seconds. The same text says that we have as many breaths in one muhurta (1/30 of a day or 48 minutes) as there are days and nights in the year or 720, so this connection of the outer light and our inner processes is quite detailed at an early period.
In Vedic thought the subtle body is composed of the five elements, the five sense organs and five motor organs, which correspond to different aspects of its five lower chakras .On top of these five are the mind and intellect (manas and buddhi) which are often compared to the Moon and the Sun and relate to the two higher chakras. They can be added to these other five factors, like the five planets, making seven in all. The chakras of Dirghatamas, though outwardly connected to the zodiac, are inwardly related to the subtle body, a connection that traditional commentators on the hymn like Sayana or Atmananda have noted.
This hymn of Dirghatamas contains many other important and cryptic verses on various spiritual matters that are connected to but go beyond the issues of the zodiac. It is written in the typical Vedic mantric and symbolic language to which it provides two keys;
39. The supreme syllable of the chant in the supreme ether, in which all the Gods reside, those who do not know this, what can they do with the Veda? Those who know it alone are gathered here.
45. Four are the levels of speech. Those trained in the knowledge, the wise know them all. Three hidden in secrecy cannot be do not stir. Mortals speak only with the fourth.
There is clearly a hidden knowledge behind these verses, which reflect an esoteric tradition of spiritual knowledge that was mainly accessible for initiates who had the keys to open its veils. We cannot simply take such verses superficially but must look deeply and see what they imply. Then the pattern of their inner meaning can come forth. If we do this, the astronomical and astrological side cannot be ignored.
Pingree’s Views
Western scholars of the history of astronomy like David Pingree have accepted the astronomical basis of this hymn. In an article, "Astronomy in India" in Astronomy Before the Telescope, C. Walker (ed.), St. Martin's Press, New York, 1996, pps. 123-124, Pingree suggests that Mul. Apin, Babylonian tablets that date from 687 to 500 BC has "’an ideal calendar' in which one year contains 12 months, each of which has 30 days, and consequently exactly 360 days; a late hymn of the Rgveda refers to the same ‘ideal calendar’. And Mul.Apin describes the oscillation of the rising-point of the sun along the eastern horizon between its extremities when it is at the solstices; the same oscillation is described in the Aitareya Brahmana.’" This ideal calendar is the basis for the zodiac and its twelve signs at a mathematical level. Clearly Pingree is referring to Rig Veda I.164 as his ‘late’ hymn of the Rig Veda.
To quote from David Pingree’s "History of mathematical astronomy in India," in the Dictionary of Scientific Biography, C.S. Gillespie (ed.), pp. 533-633, Charles Scribners, New York, 1981, page 534: "In the case of the priority of the Rgveda to the brahmanas, it is not always clear that the views expressed in the latter developed historically after the composition of the former. All texts that can reasonably be dated before ca. 500 BC are here considered to represent essentially a single body of more or less uniform material." The point of his statement is to try to get such Rig Veda references as those of Dirghatamas later than the Brahmana texts as both reflect a similar sophisticated astronomy, which is necessary to make it later than the Babylonian references and a product of a Babylonian influence as he proposes. This requires reducing all the layers of Vedic literature to a more or less uniform mass at a very late date, which is contrary to almost every view of the text.
Clearly this Rig Veda hymn, which has parallels and developments in the Brahmanas (like the Shatapatha Brahmana quoted in this chapter), must be earlier and show that such ideas were much older than the Brahmanas. To maintain his late date for Vedic astrology, Pingree must assume that this hymn or its particular astronomical verses were late interpolations to the Rig Veda, around 500 BCE or about the time of the Buddha. This is rather odd because the Buddha is generally regarded as having come long after the Vedic period, while the actual text is usually dated well before 1000 BCE (some have argued even to 3000 BCE).
Even the Brahmanas, like the Upanishads that come after them, are pre-Buddhist by all accounts. Perhaps the main Vedic ritual given in the Brahmanas, the Gavamayana, follows the model of a year of 360 days and is divided into two halves based upon the solstices, showing that such an ‘ideal’ calendar was central to Vedic thought. That such an ideal calendar has its counterpart in the sky is well reflected in Vedic ideas saying that equate the days and nights with the Sun’s rays and with the stars (as we have noted in Shatapatha Brahmana with 720 Upanakshatras)*. The Brahmanas, we should also note, emphasize the Krittikas or the Pleiades as the first of the Nakshatras, reflecting an astronomical era of the Taurus equinox. The Shatapatha Brahmana notes that the Krittikas mark the eastern direction.
In addition, the hymn, its verses and commentaries on them are found in many places in Vedic literature, along with support references to Nakshatras. It cannot be reduced to a late addition but is an integral part of the text.
That being the case, a zodiac of 360 degrees and its twelvefold division are much older in India than any Greek or even Babylonian references that he has come up with.
Pingree also tries to reduce the ancient Vedic calendar work Vedanga Jyotish to 500 BCE or to a Babylonian influence. However, the internal date of this late Vedic text is of a summer solstice in Aslesha or 1300 BCE, information referenced by Varaha Mihira in his Brihat Samhita (III.1-2). "There was indeed a time when the Sun’s southerly course (summer solstice) began from the middle of the Nakshatra Aslesha and the northerly one (winter solstice) from the beginning of the Nakshatra Dhanishta. For it has been stated so in ancient works. At present the southerly course of the Sun starts from the beginning of Cancer and the other from the initial point of the sign Capricorn." The middle of Aslesha is 23 20 Cancer, while the beginning of Dhanishta (Shravishta) is 23 20 Capricorn. Calculating the precession accordingly, this is obviously a date of around 1300 BCE.
There are yet earlier references in the Vedas like Atharva Veda XIX.6.2 that starts the Nakshatras with Krittika (the Pleiades) and places the summer solstice (ayana) in Magha (00 - 13 20 Leo), showing a date before 1900 BCE. These I have examined in detail in my book Gods, Sages and Kings (Lotus Press). Clearly the Vedas show the mathematics for an early date for the zodiac as well as the precessional points of these eras long before the Babylonians or the Greeks supposedly gave them the zodiac.
It is not surprising that India could have invented the zodiac and circle of 360 degrees. After all, the decimal system and the use of zero came from India. In this regard, as early as the Yajur Veda, we find names for numbers starting with one, ten, one hundred and one thousand ending with one followed by twelve zeros (Shukla Yajur Veda XVII.2).
The Rig Veda has another cryptic verse that suggests its cosmic numerology. According to it the Cosmic Bull has four horns, three feet, two heads and seven hands (Rig Veda IV.58.3). This sounds like a symbolic way of presenting the great kalpa number of 4,320,000,000 years. Such large numbers for the universe are typical to Indian thought, but scholars such as Pingree would also ascribe them to a Babylonian origin. However, the literature suggests the opposite.
Planets May Affect the Chemistry of Their Stars: Scientific American
Planets May Affect the Chemistry of Their Stars: Scientific American
Planets are, by and large, at the mercy of their stars. Not only do stars provide a ready energy source of radiated light and heat, but the mass and gravitational pull of stars flat-out dwarfs the summed masses and pulls of any orbiting companions. In our solar system, which has more planets—regardless of where one stands on the Pluto debate—than any other planetary system we know of so far, the sun still makes up more than 99.8 percent of its system's mass.
But a new survey of stellar chemistry in solar-type stars reveals at least one way that pip-squeak planets can strike back, affecting the evolution of their parent stars. A paper in the November 12 issue of Nature shows that lithium is greatly depleted in stars known to host planetary systems compared with otherwise similar stars that appear to be barren of planets. (Scientific American is part of the Nature Publishing Group.)
A correlation between stellar lithium abundances and the presence of planetary systems had been suspected for years—our lithium-weak sun, for one, certainly fits the bill. But the catalogue of stars with such extrasolar planets, or exoplanets, was too small to evaluate the relationship with statistical confidence. In the past dozen years, however, numerous exoplanetary discoveries have been announced, including a suite of 30 new planets unveiled in October by the European Southern Observatory's HARPS planet-finding collaboration that boosted the full set of known exoplanets to more than 400.
Study co-author Nuno Santos, an astrophysicist at the Center for Astrophysics at the University of Porto in Portugal, and his colleagues took chemical-abundance data, derived from precision light spectra, on 133 stars of roughly sunlike temperature from the HARPS survey, 30 of which are known to harbor planets. (They also added more than two dozen other stars to the population to boost the sample size.) The vast majority of stars with planets were excessively depleted in lithium, whereas most "single" stars were only partly depleted. And in a subset of the 84 stars closest to the sun's temperature, the correlation was even stronger.
The researchers suspect that the presence of orbiting planets may increase convective mixing in the host star, plunging the lithium into its hotter regions where nuclear reactions consume the light element as fuel. "We know that lithium depletion in a star is dependent on the history of the star, how it rotates through its history," Santos says. "The presence or formation of planets could change this rotational history of the star."
But might lithium-depleted stars simply be more amenable to planet formation? Not likely, Santos says. "I don't think that's the reason, because actually lithium is not supposed to play any role in planet formation," he says. "There are only very small quantities of lithium, so it's not acceptable that lithium is, by itself, influencing planet formation. The idea is that things come the other way around. By some process, the planet-formation process is influencing the depletion of lithium in the atmosphere of the stars."
Whatever the reason, a simple lithium measurement—in concert with characteristics such as stellar mass and other chemical abundances—might aid future exoplanet hunters in pegging the stars that are most likely to bear planetary fruit.
Planets are, by and large, at the mercy of their stars. Not only do stars provide a ready energy source of radiated light and heat, but the mass and gravitational pull of stars flat-out dwarfs the summed masses and pulls of any orbiting companions. In our solar system, which has more planets—regardless of where one stands on the Pluto debate—than any other planetary system we know of so far, the sun still makes up more than 99.8 percent of its system's mass.
But a new survey of stellar chemistry in solar-type stars reveals at least one way that pip-squeak planets can strike back, affecting the evolution of their parent stars. A paper in the November 12 issue of Nature shows that lithium is greatly depleted in stars known to host planetary systems compared with otherwise similar stars that appear to be barren of planets. (Scientific American is part of the Nature Publishing Group.)
A correlation between stellar lithium abundances and the presence of planetary systems had been suspected for years—our lithium-weak sun, for one, certainly fits the bill. But the catalogue of stars with such extrasolar planets, or exoplanets, was too small to evaluate the relationship with statistical confidence. In the past dozen years, however, numerous exoplanetary discoveries have been announced, including a suite of 30 new planets unveiled in October by the European Southern Observatory's HARPS planet-finding collaboration that boosted the full set of known exoplanets to more than 400.
Study co-author Nuno Santos, an astrophysicist at the Center for Astrophysics at the University of Porto in Portugal, and his colleagues took chemical-abundance data, derived from precision light spectra, on 133 stars of roughly sunlike temperature from the HARPS survey, 30 of which are known to harbor planets. (They also added more than two dozen other stars to the population to boost the sample size.) The vast majority of stars with planets were excessively depleted in lithium, whereas most "single" stars were only partly depleted. And in a subset of the 84 stars closest to the sun's temperature, the correlation was even stronger.
The researchers suspect that the presence of orbiting planets may increase convective mixing in the host star, plunging the lithium into its hotter regions where nuclear reactions consume the light element as fuel. "We know that lithium depletion in a star is dependent on the history of the star, how it rotates through its history," Santos says. "The presence or formation of planets could change this rotational history of the star."
But might lithium-depleted stars simply be more amenable to planet formation? Not likely, Santos says. "I don't think that's the reason, because actually lithium is not supposed to play any role in planet formation," he says. "There are only very small quantities of lithium, so it's not acceptable that lithium is, by itself, influencing planet formation. The idea is that things come the other way around. By some process, the planet-formation process is influencing the depletion of lithium in the atmosphere of the stars."
Whatever the reason, a simple lithium measurement—in concert with characteristics such as stellar mass and other chemical abundances—might aid future exoplanet hunters in pegging the stars that are most likely to bear planetary fruit.
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