re gamma ray bursters positional stuff in article rmh einn h gap caltech edu kwp wag caltech edu kevin w plaxco writes in article apr stdvax gsfc nasa gov abdkw stdvax gsfc nasa gov david ward writes given that fact and the spacecraft attitude knowledge of approx arcmin we might be able to figure out how well batse can determine the location rotational of a gamma ray burster from knowledge of the all sky map s accuracy pr material for the other three instruments give accuracies on the order of fractions of a degree if that s any help but i believe that there is a fundamental difference here the other x three instruments are focusing instruments that more or less form an image so positional errors are limited by craft attitude and the resolving power of the optics batse is an altogether different beast effectively just coincidence counters one on each corner of the craft positional information is triangulated from the differential signal arrival times at each of the detectors positional error would be predominantly determined by timing errors and errors in craft attitude since none of the baste detectors have any independant angular resolution whatsoever they can not be used to determine parallax indeed parallax would just add a very small component to the positional error demonstrating that these puppies are beyond the oort cloud would require resolution on the order of arcseconds since the oort cloud is postulated to extend to about parsec all together now parallax arc second a parsec is the distance of an object that demonstrates one arc second of parallax with a au base line if the degree accuracy reported above is true we re going to have to add a baste to the pluto fast flyby to get enough baseline the beauty of baste is that it both gives positional information and watches the entire sky simultaneously a realy handy combination when you have no idea where the next burst is coming from kevin batse alone isn t always used to determine position when a particularly bright burst occurs there are a couple of other detectors that catch it going off pioneer or is the one i m getting at here this puppy is far enough away that if a bright burst happens nearby the huge annulus created by it will hopefully intersect the line or general circle given by batse and we can get a moderately accurate position say oh or degrees that is the closest anyone has ever gotten with it actually my advisor another classmate of mine and me were talking the other day about putting just one detector on one of the pluto satellites then we realized that the satellite alone is only carrying something like pounds of eq well a batse detector needs lead shielding to protect it and alone weighs about pounds itself we decided against it jeremy
