Separated Fringe Packet Observations with the Chara Array. 1. Methods and New Orbits for chi Draconis, HD 184467, and HD 198084

We present the modification of the orbits of chi Draconis and HD 184467, and a completely new orbit for HD 198084, including data taken at the Center for High Angular Resolution Astronomy (CHARA) Array. These data were obtained using a modification of the technique of separated fringe packets (SFPs). The accuracy of the SFP data surpasses that of data taken by speckle, but the technique is much more time and labor intensive. Additionally, using SFPs with the CHARA Array, it is possible to obtain separations below the detection range of speckle interferometry (greater than or equal to 30 mas) above the range in "classic" long-baseline interferometry where fringes from a binary overlap are no longer separated (less than or equal to 10 mas). Using spectroscopic binary systems with published speckle orbits, we are able to test our new measurements against their ephemerides to calibrate the method as well as produce entirely new orbits for systems with no current astrometric observations.
Published in the Astronomical Journal, v139 p2308-2318, June 2010.