Other OSETI Projects Optical SETI at the University of California Two OSETI projects are being planned at this American university: The pulse search The Berkeley pulse search will observe 2500 nearby stars, mostly of F, G, K and M type (the Sun is of type G), along with a few globular clusters and nearby Galaxies. It will search for very short bright pulses of light, lasting for no more than a billionth of a second, using the 30-inch automated telescope at the Leuschner Observatory. The instrument package splits the light received by the telescope into two beams that are directed to a pair of very high speed photomultiplier tubes. A coincidence detector will eliminate "false alarms" that can be caused by radioactive decay and scintillation in the glass of the photomultipliers. The narrow line search It is also possible that a civilisation might have the technology to send out a laser signal continuously. In such a case it is expected that the signal would occupy an ultra-narrow wavelength band. In another project, it is hoped to search the spectra of around 1000 stars, many of which have already been taken during another research project, the search for exoplanets by Marcy and Butler. In this sense it is a "piggyback" system which has the great advantage that data are coming in from some of the world's largest optical telescopes which are taking part in the ongoing planet searches. The SETI Institute The SETI Institute is building an optical SETI instrument in collaboration with the Lick Observatory (California), initially mounted on the Nickel 1-metre aperture telescope at that observatory. Their system uses three photomultiplier tubes rather than two. The twin tube systems still appear to give false coincidences around once per day which is rather frustrating. The triple coincidence system should reduce this to perhaps once false trigger per year. OSETI in Australia The problems of false detections will be overcome in a project being developed in Australia by Ragbir Bhathal at the University of Western Sydney. He will use two telescopes of 0.3 and 0.4 metres in separate domes 20 metres apart. The twin system will be dedicated to observe around 200 stars and some globular clusters and galaxies.

The 30" automated telescope used in the Berkeley OSETI programme A spectrogram of the bright star Procyon. Such spectra are being examined in an attempt to find very narrow emission lines that might reveal the presence of a civilisation on a planet in orbit around the star. The Meade LX200 telescope in one of the two domes at the University of Western Sydney (Australia).