University Astronomers Plan Trip To Ceylon Next Month for Eclipse

Three University astronomers will fly to Ceylon early next month to study the sun's corona during the longest solar eclipse in over 1200 years. Groups from throughout the United States and foreign countries will converge on the Island for the June 20 eclipse, including several which will conduct a major test of one of the late Albert Einstein's most famous predictions.

"All the astronomers hope to take advantage of the unusually long eclipse to reduce the error unavoidable in observations during shorter eclipses," said William M. Sinton, Research Associate in the College Observatory and leader of the University group.

The eclipse will be visible only in a narrow strip of the earth's surface beginning in the Indian Ocean and extending east across Ceylon into the Pacific Ocean north of the Solomon Islands. The maximum totality will be seven minutes, seven and nine-tenths seconds, the longest since 717 A.D. Not until 2150 A.D. will another eclipse be that long, Sinton said.

The University group hopes to determine whether the light of the sun's inner corona, a glowing gaseous envelope surrounding the sun, is white or slightly colored. "Previous observations have shown no trace of color, but they have at best been only accurate to within 10 percent," said Sinton. "We hope, with luck, to reduce the margin of error to one percent," he added.

The Einstein prediction that a ray of light bends noticeably when passing a massive body like the sun has been checked several times, according to Sinton, but never with the accuracy that should be possible this time.

Accompanying Sinton will be Owen J. Gingerich 4G, an astronomy student, and Harold Zirin, research fellow in Astronomy. "No unusual discoveries are expected," said Sinton, "but they seldom are. And then again, it might even be cloudy."