How Near the Quasar?

Are quasi-stellar sources, or quasars, the most distant objects ever seen by man, occupying the outer limits of the universe itself? Or are the quasars relatively close by, perhaps even neigh bors of the earth's own Milky Way galaxy? These questions have divided scientists into warring camps and brought near chaos to the once orderly world of astronomy. To confuse the issue further, a staunch advocate of the distant-quasar theory has now weakened his own case by finding evidence suggesting that one quasar is closer to earth than most nearby galaxies.

After analyzing photographs of qua sar 3C 287, University of Maryland Astronomer Thomas Matthews esti mates that the starlike object may be no farther away than 1,000,000 light-years -- or about six quintillion (6 followed by 18 zeros) miles. Although this distance is staggering by earthly standards, it is a mere stone's throw in the vastness of the universe. Distances of remote galaxies, for example, are estimated at billions of lightyears, and quasar 3C 287 was believed to be five billion light-years away. Some quasars are believed by many astronomers to be even more distant.

Sudden Thickening. Matthews reported to an American Astronomical Society meeting in Philadelphia that he discovered his clue to the distance of 3C 287 when he compared older photo graphs taken of the quasar in 1950 and 1965 with another taken in 1966.

On some earlier plates, 3C 287 ap peared to consist of a bright blue starlike object joined to a fainter red companion by a luminous band, or bridge.

In 1966, however, the bridge suddenly became five times as wide as it was the previous year.

Whatever the cause of its sudden thickening, Matthews reasoned, the bridge could not have grown faster than the velocity of light, which is the uni versal speed limit. Thus the maximum distance that the bridge could have expanded in any direction in the course of a year was one lightyear. Measuring the image of the bridge on the photographic plates, the astronomer determined that between 1965 and 1966, the bridge expanded outward on each side by a distance occupying two seconds of arc-of the sky. If the bridge covered two additional seconds of arc by growing a light-year in any direction, he then calculated, it could be not farther than 1,000,000 light-years away.

Ironically, Matthews helped identify the first known quasar, 3C 48, in 1960, a finding that eventually led to the discovery by Astronomer Maarten Schmidt (TIME cover, March 11, 1966) that light from quasars showed a great red shift. This convinced most astronomers--including Matthews--that, despite their brightness, the starlike objects are as far or farther away than the most distant galaxies and are thus the most energetic objects in the universe. Astronomer Matthews' distant-quasar view has not been shaken too violently by his new finding. "Just because 3C 287 may be relatively close to us," he says defiantly, "we don't have to conclude that the other quasars are close too."

*A second of arc is 1/3600 of 1DEG.

This file is automatically generated by a robot program, so reader's discretion is required.