Speckle Observations of Composite Spectrum Stars with PISCO in 1993-1998
Festou, M. C.; Arnold, L.; Scardia, M.; Ginestet, N.; Prieur, J. -L.; Aristidi, E.; Koechlin, L.; Carquillat, J. -M.; Morel, S.; Avila, R.; Pérez, J. -P.
France, Italy, Mexico, Germany
Abstract
We present speckle interferometry observations of 47 composite spectrum stars obtained between 1993 and 1998 at the Pic du Midi Observatory with the PISCO speckle camera. 76% of over 150 independent 10 minute sequences of observations led to a companion detection. Binary component angular separations ranged from 0.05" to 1.2". We also obtained a series of 23 measurements of an additional nine close binaries. PISCO observations confirm, for the first time since their discovery, the duplicity of HD 29104 (L4), HD 83808 (WGT 1Aa), HD 183912 Aa' (BON Ap), and HD 156729 (HR 6436). Discovered as double by Hipparcos, the particularly difficult to resolve HD 156729 was observed despite the large magnitude difference, Δm=4.2, between its two components. Based on observations made with the Télescope Bernard Lyot at Pic du Midi Observatory, France.