2007/06/18 by Andreas Seifahrt, A. Seifahrt, Tristan Roell +3
Engineering · Physics and Astronomy · #Adaptive optics and wavefront sensing #Astrometry #Astronomical Observations and Instrumentation #Binary number #Differential (mechanical device) #Ephemeris #Exoplanet #Filter (signal processing) #Planet #Refraction #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1007/978-3-540-76963-7_37
To be published in the proceedings of the 2007 ESO Instrument Calibration Workshop
arxiv created 2007/06/18 · openalex publication_date 2008/05/04 · arxiv updated 2015/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Relative astrometric measurements with a precision far better than 1 mas (milli-arcsec) are commonly regarded as the domain of interferometry. Pioneering work by Pravdo & Shaklan (1996), made in the optical, reached a precision of 150 micro-arcsec in direct imaging but is ultimately limited by atmospheric turbulence and differential chromatic refraction (DCR) effects. Neuhaeuser et al. (2006, 2007) demonstrated that AO assisted observations with NACO in a near-infrared narrow band filter allow measurements with a precision of ~50 muas (micro-arsec) on a 0.6 arcsec binary within one hour and are unaffected by DCR effects. This opens new possibilities for astrometric detections of extrasolar planets and the determination of their true masses. We discuss here how to improve the measurements and address the necessary calibrations.