Speckle observations with PISCO in Merate (Italy): XV

Abstract

We present relative astrometric measurements of visual binaries, made in 2014 with the speckle camera Pupil Interferometry Speckle camera and COronagraph (PISCO) at the 102-cm Zeiss telescope of Brera Astronomical Observatory, in Merate. Our observing list contains orbital couples as well as binaries whose motion is still uncertain. We obtained 224 new measurements of 218 visual binary stars, with angular separations in the range 0 ′′ .15-10 ′′ , and an average accuracy of 0 ′′ .015. The mean error on the position angles is 0 • .5. Most of the position angles were determined without the usual 180 • ambiguity with the application of triple-correlation techniques and/or by inspection of the long integration files. We complete this data with the results of a study of the multiple system ADS 6993 with PISCO during the period 2004-2014 and propose a new method to resolve part of the 180-degree ambiguity with the autocorrelations only. We then present new revised orbits for ADS 671, 1615, 1709, 5447, 10075, and 12447, partly derived from PISCO observations. The corresponding estimated values for the masses of those systems are compatible with the spectral types.

Detecting Water in the Atmosphere of HR 8799 c with L-band High-dispersion Spectroscopy Aided by Adaptive Optics

“…This is used to convert the planet-star separation in the unit of arcsec to pixels along slit. HO 482 AB (Prieur et al 2014) was chosen from the Sixth Catalog of Orbits of Visual Binary Stars (Hartkopf et al 2001) 6 . At the time 6 http://ad.usno.navy.mil/wds/orb6/orb6frames.html of observation (UT 2016 Aug 14), the position angle and angular separation were 15.10 degree and 0.558 for HO 482 AB.…”

“…The actual uncertainty of plate scale may be larger because of systematic errors in determining the orbit of the astrometric standard star, HO 482 AB. According to Prieur et al (2014), we estimated the actual uncertainty of plate scale to be 0.001 .…”

Speckle observations with PISCO in Calern (France): I. Astrometric measurements of visual binaries in 2015–2016

“…The purpose of this article is to contribute to a better knowledge of the apparent relative motion of long‐period binaries so that very accurate orbits could be determined in the future and fundamental parameters such as stellar masses could be inferred from them. This article opens up a new series that will be the counterpart of the series of articles that have reported the results of observations with PISCO in Brera Astronomical Observatory (Merate, Italy): Scardia et al , , , , Prieur et al , Scardia et al , Prieur et al , Scardia et al , Prieur et al , Scardia et al , Prieur et al , Scardia et al , Prieur et al , Scardia et al , Prieur et al , and Scardia et al , herein: Papers I to XVI. The focal instrument PISCO (Prieur et al ) was developed at Observatoire Midi‐Pyrénées (France) and first used at Pic du Midi observatory (France) from 1993 to 1998.…”

Speckle observations with PISCO in Merate (Italy): XVI. Astrometric measurements of visual binaries in 2015, and new orbits for DUN 5, ADS 5958, 6276, 7294, 8211, and 13169

“…This paper presents the results of speckle observations of visual binary stars made in Merate, Italy, in 2015 with the Pupil Interferometry Speckle camera and COronagraph (PISCO) on the 102‐cm Zeiss telescope of INAF—Osservatorio Astronomico di Brera (OAB, Brera Astronomical Observatory). It is the sixteenth of a series whose purpose is to contribute to the determination of binary orbits (Prieur et al , , , , , ; Scardia et al , , , , , , , , , herein: Papers I–XV). The focal instrument PISCO was developed at Observatoire Midi‐Pyrénées (France) and first used at Pic du Midi from 1993 to 1998.…”