This widget handles initial single orbit fits to improve the apparent ellipse or orbit as determined by the ELLIPSE and ORBIT utilities in the ORBITPLOT widget. The procedure is as follows: the user defines an ellipse first, then fits the apparent ellipse to the binary positions using ASTROMETRYELLIPSE. Then ORBITPLOTUTILORBIT is used to estimate the orbital elements, which are then improved by ASTROMETRYFITORBIT. If the fit was successful, ASTROMETRYFITSETMODEL will store the elements in the appropriate model component.