Rahu and Ketu are said to be two imaginary points of intersection in the apparent paths of the Sun and the Moon. From Aryabhatta´s time onwards Indian astronomers were the only ones who could accurately predict when eclipses would occur, till Keplar wrote his laws in the 17th century.

Rahu is one of the nodes of the two eclipses visible from the Earth-the Solar and the Lunar. In Hindu mythology, he is depicted wearing black clothes, seated on a throne and placed south west of the Sun. Rahu is tall in stature and slow by nature. He is the one who cures diseases, the one who bestows freedom from fear of snakes and poisonous reptiles. He is full of mercy and is a friend of Shani and Shukra.

Tirunageshwaram

This vast temple known is for its shrine to Rahu, one of the nine celestial bodies in the Navagraha. It is about 5 km from Kumbakonam. It is huge temple built in about 15 acres, This temple is one of the biggest in Tamil Nadu. It was built in stages from the tenth century.

The presiding deity is Nageshwara and his consort his Girikuchambika.

The shrine to Rahu as Nagaraja with consorts Simhi and Chitralekha is situated in the South-west corner. This temple is considered next only to Kashi in holiness. A legend has it that the mythological serpents Adiseshan, Dakshan and Kaarkotakan worshipped Shiva here. Legend also has it that King Nala worshipped Shiva here as in Thirunallar.

The childless pray here for children. The mentally ill are said to be cured on visiting this temple. The belief is that worshippers of Naganatha will not suffer any ill effects from snake and scorpion bites.Rahu bestows great wealth on his devotees.

A period of one and half hours is set apart every day as Rahu Kaalam i.e.,Rahu´s Time. Auspicious events like marriages, starting on a journey are to be avoided during this time. But during Rahu Kaalam, pooja is performed every day to Rahu at Thiru Nageshwaram. Rahu is bathed in milk during the pooja. Participating in the pooja, ensures success in one´s endeavours as well as victory over one´s enemies.

The temple is open daily between 6.30 am to 1pm, 4pm to 9 pm.

The town is famous for its dhoties which are manufactured here.

Ketu

Ketu is Rahu´s complementary node of the eclipse. He is depicted with the head of a red serpent and the body of a man. Ketu is black in colour and his chariot is said to be drawn by ten horses. He is said to be angry by temperament and tall in stature. Being dark, he is called Kaala. He is believed to be a eunuch.

Keezhperumpallam

This is an ancient temple situated in the tiny village of Tiruvalampuram, about 65 km from Kumbakonam,

The presiding deity here is Valampurinatha aalias Naganathaswami. His consort is Soundara Nayaki. There is a small shrine dedicated to Nagaraja who is also worshipped as Ketu in this temple. The idol of Ketu is visible through the entrance with a silver serpent on the arch.

Legend has it that Kethu, the other planetary node of the nine celestial bodies worshipped Shiva here. He is depicted as a five-headed Cobra with the body of a human, praying to Shiva with folded hands, Rahu and Kethu are associated with the legend of the serpent that helped Lord Shiva churn the milky ocean.

Ketu augments the boons granted by the other Grahas. For example, if Shukra is favourably placed, Ketu can make a person rich beyond his expectations. Similarly, in conjunction with Guru, Ketu can assist a bright student to perform brilliantly or ensure unexpected promotions at one´s workplace. Ketu is the Graha in charge of progeny. One is blessed with good children if one prays to him. A comfortable and affluent lifestyle or a stint abroad could also be Ketu´s gifts.

Srivanjiyam

This is the lesser known of the two Ketu temples. It is situated about 35km from Kumbakonam. The presiding deity here is Vanjinathar and his consort is Mangalambila. The temple is large and impressive. It was built in the 12th century AD.

The temple is open daily between 7 am to 12.30 pm, 4.30 pm to 8 pm.