Basic Astronomical facts about Sun
Sun, the largest body and a star at the center of our solar system it is made mostly of hydrogen and helium, has a diameter of about 1.4 million kilometers. It contains more than ninety-nine percent of total mass of our solar system. Its mean distance from the earth is about 149 million kilometer. Its average geocentric motion per day is 00°59'08". The Sun never seems retrograde as it is stationary and located in center of solar system and all the planets revolve around it.

Sun in Hindu Mythology
The Sun God is the source of all life and energy that exist in the universe. In hindu mythological, the abode of Sun god is known as Suryaloka, and this sphere is next to the physical world or bhu-mandala. Sage Kashyap and his wife Aditi gave birth to Indra, Visnu, Vivasvan, Miter, Amsuman, Dhata Tvasta, Pusa, Varuna, Aryama, Bhaga and Savita. These twelve sons of Aditi become know as twelve Adityas. Lord Bramha selected Savita from theses twelve Adityas and blessed him by saying only he will be worshiped and all other Adityas will be merged in him. But these twelve Aditayas exerts their force separately which gave rise to twelve months and each of them are said to rule over the each of the twelve months. As a result of this, we have different seasons and climatic changes.

The Sun god's wife Sanjana was the daughter of Vishvakarma, the celestial architect. They had three children Vaivasvata, Yama (the god of death) and Yami. Sanjana was having tough time with Sun, not because of any discord between them but as Sun's light was too strong for her. One day Sanjana decided to go away from home, leaving in her place her body double, Chaaya (shadow). For some time, Sandhya lived with her father and then left it too, she took the form of a mare and went to the mountains to pray. Meanwhile, the Sun being unknown of this fact, continued to live with Chaaya and she gave birth to three more children, Savarni, Shani (later became the planet Saturn) and Taapti (later became a river). After passage of some more time Sun realized that Chaaya was not his wife and he went to look for her. He saw his wife praying in the form of a mare and he turned himself into a horse and approached her amorously. This led to the birth of horse headed twins, Ashwini Kumara, the celestial physicians. Sanjana told her husband that his light was too strong for her. Sun then decided to divide his light in to sixteen parts, each of which created different planets including Earth, while the Sun was left with one-sixteenth part of his original light and Sanjana came back to live with Sun.

The Sun's chariot is driven by Arun and have seven horses pulling the chariot, known as Gayatri, Brhati, Usnik, Jagati, Tristup, Anustup and Pankti. These seven horses are metaphorically speaking are the seven colors which the Sunlight consists of and know as 'VIBGYOR'. A powerful race of hindu kings are supposed to be the direct descendant of Sun god. This dynasty know as Suryavanshi, first king of this dynasty was Iskwakoo and later incarnation of Vishnu, Lord Rama was born in this dynasty. Names mentioned for the Sun in hindu mythology are Ravi (praised by all), Aditya (of Aditi, inspirer), Surya (the supreme guide or light), Bhaanu (the shining one or ray of light), Arka (the radiant), Bhaskara (the illuminator), Mitra (friend of all), Marichi (rays of light, starlight), Sahasrarhsu (having thousand rays), Savita (the purifier), Pushan (the nourisher of all), Khag (stimulator of the senses), Mihira , Prabhakara (creter of shining light), Martanda (sprung from lifeless egg), Chitrabhanu (lord of flames), Divakara (creator of day) and Hiranyagarbhaya (having golden womb, the creator).

Body parts, function and diseases governed by Sun
The Sun is the life giver to our physical bodies and controls the prana or life force. The placement of the Sun is very important for overall health as it governs entire constitution of the body. No number of words can express the Sun's importance in bodily functioning. It specifically rules the heart, eyes, upper back and spine, aorta and blood circulation. Every heart related problem arise due to affliction to Sun or its sign Leo, this includes enlarged heart conditions, palpitations of the heart, cholesterol-related degeneration of the heart, angina, pericarditis, endocarditis, blood pressure and heart attacks. High fevers, back problem, diseases of the bone marrow, rheumatic fever and sunstroke.

Professions governed by the Sun
Any profession or employment having authority, command and power. Generally any service under Government but specifically high posts like department heads, envoy, ambassador, counsel general, ministers, etc. Employment in fields related to gold, manufacturing and trading in wool and woolen goods, wood and wooden furniture. Traders of wheat, grains, pulses and cereals. Career related to bankers, presidents, stock exchange, engineering, occupations involving children and related to entertainment, amusement and theaters. Service in medical department, particularly heart and child specialist.

The Mantras for Sun:
Beej Mantra of Sun:
Om hram hreem hroum sah suryaye namah

The Sun Stotra:
Om Jaba kusuma sankasam kashyapeyam mahadutim tamorim sarva paapghnam pranatosmi Divakaram

Gayatri Mantra of Sun:
Om Adityaye vidmahe divakaraya dhimahi tanno suryay prachodayat

Remedies for Sun if it is malefic in Horoscope.
1. Worshiping the ruling deity of the Sun, Lord Shiva.
2. Recitation of Aditya Hridaya Stotra.
3. Reciting of Sun Mantras.
4. Charity: Donate wheat or jaggery on Sundays.
5. Fasting day: Sundays.
6. Pooja: Rudrabhishek.
7. Wear One mukhi (One faced) Rudraksh.
8. Surya Namaskar: a simple twelve step exercise to be performed at the time of Sunrise facing east.
9. Do not eat non-vegetarian food on Sundays.
10. Do not consume alcohol on Sundays.

(It is not necessary to perform all the listed remedies; you can choose few of them)

Details About Other Planets
Moon in Astrology, Mercury in Astrology, Mars in Astrology, Jupiter in Astrology, Saturn in Astrology, Venus in Astrology and Rahu & Ketu in Astrology