Speckle observations with PISCO in Merate -- I. Astrometric measurements of visual binaries in 2004

Abstract

We present relative astrometric measurements of visual binaries made with the Pupil Interferometry Speckle camera and Coronagraph (PISCO) at the 1‐m Zeiss telescope of Brera Astronomical Observatory, in Merate. We provide 135 new observations of 103 objects, with angular separations in the range 0.1–4.0 arcsec and with an accuracy better than ∼0.01 arcsec. Our sample is made of orbital couples as well as binaries whose motion is still uncertain. Our purpose is to improve the accuracy of the orbits and constrain the masses of the components. This work already leads to the revision of the orbits of three systems (ADS 5447, 8035 and 8739).

Adaptive Optics Photometry and Astrometry of Binary Stars. II. A Multiplicity Survey of B Stars

“…The star was observed before our observation on 1997.1255 ) and after our observation on 2004.095 (Scardia et al 2005). Both measurements have a position angle of 242.8…”

Preliminary orbital elements of six visual binary stars

“…Since the installation of PISCO on the 102-cm Zeiss telescope in 2004, this raises to fourteen the total number of the published orbits, that we have computed with measurements obtained in Merate (Scardia et al 2005(Scardia et al , 2006(Scardia et al , 2007a(Scardia et al ,b, 2008.…”

“…Since 2004 it has been mounted and operated at the Cassegrain focus of the INAF-OAB, 102-cm Zeiss telescope in Merate. Details about the data reduction procedure and the PISCO measurements used for this work can be found in Scardia et al (2005Scardia et al ( , 2007a. The purpose of our long-term program is to provide good-quality measurements of close visual binaries in order to improve the quality of the orbits and derive estimates of the stellar masses.…”

Commission 26: Double and Multiple Stars

“…Subsequent observations confirmed the possibility of observing visual binaries with separations down to 0 .14 and with luminosity differences up to 4 magnitudes. Two papers (Scardia et al 2005a(Scardia et al , 2005b have already resulted from the observations of 2004.…”