A guidebook for observing the July 22 solar eclipse written by three Chinese teenagers has been commended by Jay Pasachoff, head of the Solar Eclipse Working Group of the International Astronomical Union (IAU).

"They provided detailed information for astronomical researchers and lovers all over the world," said Pasachoff, who visited the students' school in Hangzhou, capital of east China's Zhejiang Province, Tuesday.

The professor said he will watch the scene at one of the 23 sites recommended by the Chinese students in Tianhuangping, Anji County, Zhejiang.

World astronomers have predicted that the July 22 solar eclipse will pass over India and China in its path of totality lasting 6 minutes 30 seconds.

Wang Sichao, an expert with the Purple Mountain Observatory of the Chinese Academy of Sciences based in east China's Nanjing City,said the total eclipse to occur in the morning will be the longest of its kind in 141 years from July 11, 1991 to June 13, 2132. It can be observed in 42 cities in China's most populous Yangtze River Valley.

"The number of people watching the solar eclipse will make a historical record, since previous solar eclipses can only be best observed in desolate regions," said the expert.

The three Chinese students of the Hangzhou Senior High School started their project two years ago. They traveled 1,400 km along the solar eclipse stripe line in China with GPS devices, and selected 23 best observation spots.

Pasachoff said the guidebook with star-rankings for items such as transportation, eclipse observation sites, photographic conditions and boarding alternatives was adopted by IAU and other astronomical organizations.

Like Pasachoff, world astronomical enthusiasts has begun booking hotels in the recommended places in the guidebook as early as 2007.

"They have done a wonderful job!" said Pasachoff.

"Eclipse-observing groups from India, Japan, Sweden, Denmark and Germany have chosen their observation sites based on our recommendation," said Lin Lan, the students' supervisor.

"We felt like we are the host to receive friends to watch the eclipse. So we strived to come up with a comprehensive evaluation on the sites to help visitors enjoy a safe and fruitful trip," said Cai Tingni, one of the three students who wrote the guidebook.

She said they have researched and gathered information on the Internet, with the help of online location tools, such as Google earth, Starrynight and Skymap.

"Experts from IAU offered us a great deal of help on the writing of the book," she said.

(Xinhua News Agency July 15, 2009)