WE HAVE RECENTLY DISCOVERED A NEW -RAY LOUD LOWMASS X-RAY BINARY 3FGL J0427.9-6704. THE X-RAY AND RADIO PROPERTIES OF THIS SOURCE SUGGEST IT IS A TRANSITIONAL MILLISECOND PULSAR IN THE ACCRETING STATE. UNIQUELY AMONG MEMBERS OF THIS CLASS THIS SOURCE SHOWS OPTICAL X-RAY AND 1-RAY ECLIPSES ALLOWING PRECISE CONSTRAINTS NOT AVAILABLE FOR NON-ECLIPSING SYSTEMS SUCH AS MEASUREMENTS OF THE BINARY COMPONENT MASSES. HERE WE PROPOSE XMM X-RAY AND OPTICAL OBSERVATIONS TO BETTER UNDERSTAND THE VARIABILITY IN THE SYSTEM AND DETERMINE HOW SIMILAR ITS PROPERTFOS ARE TO THE OTHER TRANSITIONAL MILLISECOND PULSARS.

Michigan State University, East Lansing MI

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