In support of a colleague's 53-day fast to protest the nuclear arms race, 13 Harvard University professors conducted their own fast yesterday.

The group of scientists, which also included eight MIT affiliates and one University of Hawaii astronomer, pledged respect for their colleague, astrophysicist Dr. Charles Hyder.

"We are urging the government to seize a unique opportunity to reduce the nuclear peril through negotiations with the Soviet Union," said a press release from the fasters.

George B. Field, Robert Wheeler Willson Professor of Applied Astronomy, said that the group is fasting to express personal support for Hyder's activism. "We want to draw attention to the urgency of ending the nuclear arms race and to Hyder's personal commitment," Field said.

Sheldon L. Glashow, Nobel Prize Laureate and Higgins Professor of Physics, said he viewed his day-long fast as an act of sympathy with the movement. "Reagan has a unique opportunity to save the world, an opportunity no one has had since Jesus Christ. The Russians are prepared to cooperate and we should be too," Glashow said.

Others scientists decided not to fast. "The act of fasting exerts a moral pressure because it is considered a virtuous act, but we need to concentrate on the sharing of information and logical argument," said Michael I. Ratner, a research associate at the Harvard College Observatory.

"It is not clear to me that a world in which no country will admit to having nuclear weapons and yet in which many countries can secretly build scores of weapons in a matter of months would be a safer world," said Ratner.