Speckle Interferometry

Speckle Interferometry takes hundreds or thousands of very short exposures of a binary at relatively high magnification. The short exposures freeze out atmospheric-induced smearing of the image, allowing the full resolution of the telescope (which is aperture dependent) to be realized. The images consist of many “speckles” created as the light from the binary is bent at slightly different angles by small cells of slightly different density air. The many images, each filled with many speckles, are then reconstructed into an actual image using a highly intensive computer process: bispectrum analysis (triple correlation). We use the Speckle ToolBox (STB) developed by David Rowe for bispectrum analysis. Speckle interferometry observations are made using the Fairborn Institute Robotic Observatory (FIRO) and, shortly, will be made with a PlaneWave Instruments CDK-1000 (1 meter) fully robotic telescope in Chile. We make observations in conjunction with other observatories that are also equipped for speckle interferometry such as the Boyce Astro Robotic Observatory (BARO), Montevista Observatory, and Dixon Remote Observatory (DIRO). These speckle observations are combined, for somewhat wider systems (separations > 1.0 arcsec), with observations from Gaia, United Kingdom Infrared Telescope (UKIRT), and Pan-STARRS.

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Speckle Photometry and Spectral Types of Close Binary Star Components

Speckle photometry observation of close binary stars simultaneously measures orbital positions, derives color indexes, and estimates spectral types of the individual stellar components. The observation combine the techniques of speckle interferometry for diffraction-limited astrometry, bispectrum analysis for relative flux distribution of the two components, and an adaptation of differential photometry for photometric calibration. Observations in multiple Sloan filter bands yield color indexes which are correlated with spectral type. The observations provide complimentary information to improve the quality of stellar mass estimates in binary orbit solutions as well as estimates of spectral types.