The STARE Project: A Search for Transient Astronomical Radio Emission

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Session 8 -- Radio Surveys and Techniques
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

[8.01] The STARE Project: A Search for Transient Astronomical Radio Emission

C.A. Katz, J.N. Hewitt, C.B. Moore, J.D. Ellithorpe (MIT)

Many astronomical objects are known to produce transient radio emission, including the Sun, Jupiter, flare stars, and supernovae. Other phenomena are expected to produce transient radio emission as well; gamma-ray bursts are obvious candidates. Although other attempts have been made to detect transient radio emission, to our knowledge no search has had both the sensitivity and sufficient sky coverage to motivate significant progress. We propose a three-phase approach to detect transient radio sources. In the first phase we would monitor the sky for changes in total power. Simple radiometers at geographically separated locations would allow quick and easy measurements, but would provide low sensitivity and little position information. The second phase would involve monitoring the sky with small, geographically separated, correlating arrays. The correlation and the increase in collecting area would give better sensitivity and positions. For phase three, we envision the full instrument as two or more large correlating arrays providing all-sky coverage, $1'$ position resolution, and a flux density detection limit of $\sim 10$ Jy. Such an instrument would allow either the detection of previously unseen sources, or much more stringent sky event rate upper limits than those acheived in the past.

At the time of this writing our work addresses several issues. The design and construction of sensitive, inexpensive radiometers for the first phase of the project is underway; we expect system temperatures of $\sim100$K at 611~MHz in each of two orthogonal polarization channels. A simple data acquisition system using a PC and commercial A/D converter has been devised to provide sampling rates up to 100~kHz. Investigations into the availability of accurate timing information using commercial GPS equipment have produced promising results; inter-site clock synchronization of better than $10 \mbox{ ${\mu}$s}$ should be easily obtainable. We expect the rejection of local interference to be our most difficult technical challenge; accordingly, the assessment of various sites is in progress.

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