STELLAR MAGNETIC ACTIVITY CONFUSES THE INTERPRETATION OF RADIAL VELOCITY (RV) MEASUREMENTS IMPEDING PRECISE EXOPLANETARY MASS MEASUREMENTS. SPATIALLY RESOLVED MAGNETIC FIELD MEASUREMENTS HAVE SHOWN PROMISE FOR CORRECTING THE EFFECTS OF ACTIVITY ON THE SUN BUT SIMILAR METHODS HAVE NOT BEEN DEMONSTRATED FOR DISK-INTEGRATED LIGHT THAT WOULD BE APPLICABLE TO OTHER STARS. AIMS: OBSERVE A SMALL NUMBER OF HIGHLY MAGNETICALLY SENSITIVE LINES AT ULTRA-HIGH (R>106) RESOLUTION IN DISK-INTEGRATED SUNLIGHT TO EXPLORE WHETHER THE MAGNETIC FIELD CHANGE IS RECOVERABLE (FIG. 1) AND WHETHER THIS DIRECT PROBE CAN INFORM AND ADVANCE COMPLEMENTARY TECHNIQUES. A CONCLUSIVE TEST OF A SIMPLE METHOD FOR MEASURING THE STELLAR MAGNETIC FIELD TO CORRECT RV VARIABILITY. THIS TEST WILL DETERMINE THE RESOLUTION SIGNAL-TO-NOISE RATIO AND TEMPORAL SAMPLING REQUIREMENTS NECESSARY TO INFORM FUTURE OBSERVATIONS OR INSTRUMENTATION OR IT WILL REVEAL THE OBSERVATIONAL OR MODELING LIMITATIONS OF THIS APPROACH. EITHER WAY THE RELIABLY CALIBRATED ULTRA-HIGH RESOLUTION TIME SERIES SPECTRA OF HIGHLY MAGNETICALLY SENSITIVE SOLAR LINES WILL BE A POWERFUL STARTING POINT FOR DEVELOPING AND TESTING THE ADVANCED MAGNETO-HYDRODYNAMICAL MODELS THAT ARE REQUIRED TO ACCURATELY SIMULATE SOLAR/STELLAR SPECTRA.

Carleton College, Northfield MN

Investigators