@inbook{c00fc4fa2c974a13a1a7046dd1b8e733,
title = "The Treatment of Double Stars in the Hipparcos-Tycho Programme",
abstract = "The Tycho Catalogue1 contains astrometric data and (B, V) photometry for more than one million stars. The double stars with separations wider than about 3 arcsec appear as two separate entries as if they were two single stars. Between 1.5 and 3 arcsec, the two components are possibly also separate entries, but the photometric data is somewhat less accurate. Double stars with separations as close as 0.4 arcsec were also detected in the Tycho observations, and they are flagged in the Catalogue.",
author = "Halbwachs, {J. L.} and E. H{\o}g and Makarov, {V. V.} and K. Wagner and A. Wicenec",
year = "1997",
doi = "10.1007/978-94-009-1477-3_55",
language = "English",
isbn = "978-0-7923-4793-4",
volume = "223",
series = "Visual Double Stars : Formation, Dynamics and Evolutionary Tracks. Edited by J.A. Docobo, A. Elipe, and H. McAlister. Dordrecht : Kluwer Academic, 1997.",
publisher = "Springer Dordrecht",
pages = "461--474",
editor = "Docobo, {J. A. } and A. Elipe and H. McAlister",
booktitle = "Visual Double Stars: Formation, Dynamics and Evolutionary Tracks",
}