2007/11/27 by G. T. van Belle, Gerald van Belle, G. van Belle +14 · 2 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomical interferometer #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Calibration #Computer science #Interferometry #Optics #Physics #Remote sensing #Sky #Stars #Stellar, planetary, and galactic studies #Testbed #Visibility #astro-ph
paper · pdf · doi:10.1086/526548
100 pages, 7 figures, 7 tables; to appear in the May 2008ApJS, v176n1
arxiv created 2007/11/27 · openalex publication_date 2008/04/22 · arxiv updated 2019/08/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Palomar Testbed Interferometer (PTI) archive of observations between 1998 and 2005 is examined for objects appropriate for calibration of optical long-baseline interferometer observations—stars that are predictably pointlike and single. Approximately 1400 nights of data on 1800 objects were examined for this investigation. We compare those observations to an intensively studied object that is a suitable calibrator, HD 217014, and statistically compare each candidate calibrator to that object by computing both a Mahalanobis distance and a principal component analysis. Our hypothesis is that the frequency distribution of visibility data associated with calibrator stars differs from noncalibrator stars such as binary stars. Spectroscopic binaries resolved by PTI, objects known to be unsuitable for calibrator use, are similarly tested to establish detection limits of this approach. From this investigation, we find more than 350 observed stars suitable for use as calibrators (with an additional ≈140 being rejected), corresponding to ≳95% sky coverage for PTI. This approach is noteworthy in that it rigorously establishes calibration sources through a traceable, empirical methodology, leveraging the predictions of spectral energy distribution modeling but also verifying it with the rich body of PTI's on-sky observations.