Binary Star Orbits. 3. Revisiting the Remarkable Case of Tweedledum and Tweedledee
Abstract
Two of the most challenging objects for optical interferometry in the middle of the last century were the close components of the wide visual binary STF2375. Each component of the wide pair was found to have subcomponents of approximately the same magnitude, position angle and separation and, hence, were designated by the tongue-in-cheek monikers "Tweedledum and Tweedledee" by the great visual interferometrist William S. Finsen in 1953. They were later included in a list of "Double Stars that Vex the Observer" by W. H. van den Bos in 1958. While speckle interferometry has reaped a rich harvest investigating the close inteferometric binaries of Finsen, the "Tweedles" have continued to both fascinate and exasperate due to both the great similarity of the close pairs and the inherent 180-deg ambiguity associated with interferometry. Detailed analysis of all published observations of the system has revealed several errors which are here corrected, allowing for determination of these orbital elements which resolve the quadrant ambiguity. A unique software filter was developed which allowed sub-arrays from archival ICCD speckle data from 1982 to be re-reduced. Those data, combined with new and unpublished observations obtained in 2001-2009 from NOAO 4 m telescopes, the Mount Wilson 100 inch telescope and the Naval Observatory Flagstaff Station 61-inch telescope as well as high-quality unresolved measures all allow for the correct orbits to be determined. Co-planarity of the multiple system is also investigated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 11, 2010
- Accession Number
- ADA524088
Entities
People
- Brian D. Mason
- Harold A. . Mcalister
- William I. Hartkopf
Organizations
- United States Naval Observatory