A Galactic Center Search for Extraterrestrial Intelligent Signals

Abstract

AbstractIn June 1995 we used the Parkes 64-m radio telescope to search for narrowband or pulsing signals of extraterrestrial intelligent (ETI) origin from the direction of the galactic center. This strategy was chosen so as to maximize the number of possibly detectable ETI signals within the beam, assuming that they are associated with stars and that their luminosity function is such that they can be detected at a distance of at least a few kiloparsecs. A total of 190 1.2–minute integrations were taken in a region of size 5.0° × 0.6° centered on the galactic center. Many positions in this region were observed 2 or 3 times in order to allow for the possibility of strong interstellar scintillations arising in any ETI signal. The spectrum analyzer was that of Project Phoenix, configured such that it covered both circular polarizations over a 20-MHz bandwidth centered on 1425.0 MHz. This bandwidth was divided into 28.7 million channels with separations of 0.64 Hz. The signal analysis system searched both for slow pulses (periods of at least 2 sec) and narrowband signals with drifts from 0 to 1 Hz/sec. A second antenna located 200 km away was used for immediate follow-up on all candidate signals. No signals of ETI origin were found. A later search of smoothed spectra with 640 Hz resolution also revealed no new features not attributable to manmade interference.