A long wait by sky gazers to look at a rare celestial event will end tomorrow when the longest total solar eclipse of the 21st century will be seen.

A total eclipse occurs when the Sun is completely obscured by the Moon. The intensely bright disk of the Sun is replaced by the dark silhouette of the Moon.

During the total eclipse, totality is visible only from a narrow track on the surface of the Earth.

The Indian cities through which the shadow of total eclipse passes are Bhavnagar, Surat, Ujjain, Indore, Bhopal, Sagar, Jabalpur, Varanasi, Allahabad, Gaya, Patna, Bhagalpur, Jalpaigudi, Guwahati and Dibrugarh.

The countries to witness the path of the Moon's umbral shadow are India, Nepal, Bangladesh, Bhutan, Myanmar and China.

China's largest city Shanghai will experience the total solar eclipse for five minutes, Science Popularisation Association of Communicators and Educators (SPACE) Director C B Devgun said, adding across the East China Sea, the eclipse will sweep over Japan's Ryukyu Islands and Iwo Jima.

After leaving mainland Asia, the path crosses Japan's Ryukyu Islands and curves southeast through the Pacific Ocean where the maximum duration of totality will be 6 min 38 sec.

A partial eclipse is seen within the much broader path of the Moon's penumbral shadow, which includes most of eastern Asia, Indonesia, and the Pacific Ocean, Devgun said.

Greatest eclipse occurs in the South Pacific at 8.05 IST, the axis of the Moon's shadow passes closest to Earth's center.

The magnitude of total solar eclipse will be approximately 1.080.

Tomorrow's solar eclipse will be the longest total solar eclipse in the 21st century and will not be surpassed in duration until June 13, 2132.

The next total solar eclipse will be on July 11, 2010 which will be seen in South pacific, Chile and Argentina.