Speckle observations with PISCO in Merate - VII. Astrometric measurements of visual binaries in 2007

Abstract

International audienceWe present relative astrometric measurements of visual binaries made during the first semester of 2007, with the Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102-cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our sample contains orbital couples as well as binaries whose motion is still uncertain. We obtained 226 new measurements of 214 objects, with angular separations in the range 0.15-4.5 arcsec, and an average accuracy of 0.013 arcsec. The mean error on the position angles is . Most of the position angles could be determined without the usual 180° ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. We also present the new orbits we have computed for ADS 7871, 7982 and 8128, for which our measurements lead to large residuals and/or for which the revision is justified by the significant number of observations made since the publication of the previous orbit

Speckle observations with PISCO in Merate (Italy): XIV. Astrometric measurements of visual binaries in 2013 and new orbits for ADS 1097, 5871, 7203, 7775, 9378, 9578, and 11186

“…It is the fourteenth of a series whose purpose is to contribute to the determination of binary orbits (Scardia et al 2005(Scardia et al , 2006(Scardia et al , 2007(Scardia et al , 2008aPrieur et al 2008;Scardia et al 2009;Prieur et al 2009;Scardia et al 2010;Prieur et al 2010;Scardia et al 2011;Prieur et al 2012;Scardia et al 2013;Prieur et al 2014, herein Papers I to XIII). The focal instrument PISCO was developed at Observatoire Midi-Pyrénées (France) and first used at Pic du Midi from 1993 to 1998.…”

Speckle observations with PISCO in Merate: X. Astrometric measurements of visual binaries in 2009

“…It is the tenth of a series (Scardia et al 2005(Scardia et al , 2006(Scardia et al , 2007(Scardia et al , 2008aPrieur et al 2008;Scardia et al 2009;Prieur et al 2009;Scardia et al 2010;Prieur et al 2010, herein: Papers I to IX), whose purpose is to contribute to the determination of binary orbits. PISCO was developed at Observatoire Midi-Pyrénées (France) and first used at Pic du Midi from 1993 to 1998.…”

Eight new and three recalculated orbits for binaries

“…More recent and more precise measurements offer the possibility to improve orbits already calculated (e.g. Prieur et al 2009;Hartkopf & Mason 2009b), which leads to more accurate determinations of the masses Corresponding author: zcvetkovic@aob.bg.ac.rs and distances and also towards a better understanding of stellar evolution. The present authors have been successful in calculating the first orbital elements for eight binaries for which the measurements either cover a shorter orbital arc or are grouped at segments of the orbit.…”