WE PROPOSE TO USE ARCHIVAL DATA FROM THE TRANSITING EXOPLANET SURVEY SATELLITE TO OBTAIN ROTATIONAL AND SHAPE PROPERTIES FOR AN UNTARGETED MAGNITUDE-LIMITED SAMPLE OF KNOWN MAIN BELT ASTEROIDS.} THE SURVEY'S EXTREMELY LARGE FIELD OF VIEW AND ITS UNIQUE OBSERVING CADENCE WILL ALLOW FOR DETECTION OF APPROXIMATELY 48 000 ASTEROIDS. WE WILL DETERMINE ACCURATE (U<3-) ROTATION PERIODS FOR 6 000 ASTEROIDS. SIGNIFICANTLY WE WILL MEASURE ROTATION PERIODS FOR EXTREMELY SLOW ROTATORS OBSERVATIONS THAT ARE VERY DIFFICULT TO MAKE WITH CONVENTIONAL GROUND-BASED TELESCOPES. FROM OUR PILOT STUDY WE FIND THAT 10% OF OUR OBJECTS HAVE DERIVED ROTATION PERIODS P>100 H. DUE TO THE UNTARGETED NATURE OF THE ASTEROID OBSERVATIONS WE WILL NOT BE SUBJECT TO OBSERVATIONAL BIASES TOWARD HIGHER AMPLITUDE ASTEROIDS AND WILL BE ABLE FOR THE FIRST TIME TO ESTABLISH A CLEAR PICTURE OF SLOW ROTATING MINOR PLANETS. WE WILL OBTAIN DETAILED LIGHT CURVES FOR 6000 ASTEROIDS OVER THE COURSE OF THE 2 YEAR PROJECT. THIS WILL ALLOW US TO BOTH IMPROVE UPON EXISTING ROTATION PERIODS WHILE ALSO SIGNIFICANTLY EXPANDING THE NUMBER OF ASTEROIDS WITH KNOWN ROTATION PERIODS. THE UNIQUE CADENCE OF TESS MEANS THAT THESE OBSERVATIONS ARE IDEALLY PLACED TO IDENTIFY OBJECTS WITH VERY LONG ROTATION PERIODS. THERE IS A DEARTH OF SLOW ROTATORS WITH ACCURATELY DETERMINED ROTATION PERIODS IN THE LITERATURE DUE TO THE HIGH RESOURCE COST REQUIRED E.G. MANY NIGHTS OF TELESCOPE TIME WOULD BE REQUIRED TO RESOLVE A LIGHT CURVE WITH A 100 H ROTATION PERIOD. INCREASING THE SAMPLE OF KNOWN ROTATORS WILL ALSO ALLOW US TO GET A BETTER PICTURE OF THE SHAPE AND ROTATIONAL PROPERTIES OF THESE TO-DATE UNDER-STUDIED OBJECTS. FOR A FURTHER SUBSET OF OBJECTS WE WILL OBTAIN PARTIAL OR NOISY LIGHT CURVES WHICH WILL ALLOW FOR A LOWER LIMIT ESTIMATE TO BE MADE FOR THE ELONGATION OF THESE OBJECTS. THE SHAPE DISTRIBUTION FOR POPULATIONS OF ASTEROIDS HAS BEEN DETERMINED USING SEVERAL SKY SURVEYS AND DATA RESOURCES HOWEVER UNTIL NOW THE PROPORTION OF OBJECTS WITH SLOW ROTATION PERIODS HAS NOT BEEN FULLY ACCOUNTED FOR DUE TO THE SMALL AND BIASED SAMPLE AVAILABLE TO DATE. WE PROPOSE TO OBTAIN A SHAPE DISTRIBUTION FROM THE TESS DATA ACCOUNTING FOR THESE SLOW ROTATORS AND UTILIZING ALL OF THE PHOTOMETRY OBTAINED DURING THIS PROJECT INCLUDING SPARSE OR FRAGMENTARY LIGHT CURVES. TO SUMMARIZE IN THIS PROGRAM WE WILL: (A) MEASURE THE PERIOD DISTRIBUTION FOR MBAS IN THE RANGE 5<P<700 H. (B) MODEL THE REQUIRED INTERNAL STRENGTH FOR 'EXTREME ASTEROIDS' THOSE WITH HIGH AMPLITUDE AND/OR EXTREME ROTATION PERIOD. (C) IDENTIFY OBJECTS WITH LONG (P>100 H) ROTATION PERIODS FOR FURTHER STUDY (D) UPDATE THE EXISTING SHAPE DISTRIBUTION FOR KILOMETRE-SIZE MAIN BELT ASTEROIDS ACCOUNTING FOR SLOW ROTATORS SOMETHING WHICH HAS NOT BEEN DONE TO-DATE. THE NASA SSW CALL STATES "THE SOLAR SYSTEM WORKINGS PROGRAM IS OPEN TO INVESTIGATIONS RELEVANT TO SURFACES AND INTERIORS OF PLANETARY BODIES." OUR PROGRAM WILL RETURN DETAILED INFORMATION ABOUT THE ROTATION STATE SHAPE AND POTENTIALLY INTERNAL STRENGTH OF A POPULATION OF ASTEROIDS WHICH HAS NOT BEEN EXPLORED IN GREAT DETAIL TO-DATE SLOW ROTATING OBJECTS.

Northern Arizona University, Flagstaff AZ

Investigators