Gautama Siddha, astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

, astrologer

Astrologer

An astrologer practices one or more forms of astrology. Typically an astrologer draws a horoscope for the time of an event, such as a person's birth, and interprets celestial points and their placements at the time of the event to better understand someone, determine the auspiciousness of an...

 and compiler of Indian

History of India

The history of India begins with evidence of human activity of Homo sapiens as long as 75,000 years ago, or with earlier hominids including Homo erectus from about 500,000 years ago. The Indus Valley Civilization, which spread and flourished in the northwestern part of the Indian subcontinent from...

 descent, known for leading the compilation of the Treatise on Astrology of the Kaiyuan Era

Treatise on Astrology of the Kaiyuan Era

The Treatise on Astrology of the Kaiyuan Era is a Chinese astrology encyclopedia compiled by the lead editor Gautama Siddha and numerous scholars from 714 to 724 AD during the Kaiyuan era of Tang Dynasty. The compilation is attributed to the author by 729. Its full title is regarded as the Great...

during the Tang Dynasty

Tang Dynasty

The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...

. He was born in Chang'an

Chang'an

Chang'an is an ancient capital of more than ten dynasties in Chinese history, today known as Xi'an. Chang'an literally means "Perpetual Peace" in Classical Chinese. During the short-lived Xin Dynasty, the city was renamed "Constant Peace" ; yet after its fall in AD 23, the old name was restored...

, and his family was originally from India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, according to a tomb stele uncovered in 1977 in Xi'an

Xi'an

Xi'an is the capital of the Shaanxi province, and a sub-provincial city in the People's Republic of China. One of the oldest cities in China, with more than 3,100 years of history, the city was known as Chang'an before the Ming Dynasty...

. The Gautama family had probably settled in China over many generations, and might have been present in China prior even to the foundation of the Tang Dynasty. He was most notable for his translation of Navagraha

Navagraha

Graha is a 'cosmic influencer' on the living beings of mother Bhumidevi . In Hindu astrology, the Navagraha are some of these major influencers.All the navagraha have relative movement with respect to the background of fixed stars in the zodiac...

 calendar into Chinese

Chinese language

The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...

. He also introduced Indian numerals

Indian numerals

Most of the positional base 10 numeral systems in the world have originated from India, where the concept of positional numeration was first developed...

 with zero (〇) in 718 in China as a replacement of counting rods

Counting rods

Counting rods are small bars, typically 3–14 cm long, used by mathematicians for calculation in China, Japan, Korea, and Vietnam. They are placed either horizontally or vertically to represent any number and any fraction....

.

Footnotes