Two-colour photometry for 9473 components of close Hipparcos double and multiple stars Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
A photometric analysis of the Cepheus OB3 region Results are presented on Stromgren-Crawford uvby-beta photometry carriedout at Calar Alto (Spain) for 45 stars in the Cepheus OB3 regioncovering an apparent area of 6 deg x 6 deg. The relationship of thesestars with the association is examined. Three of these stars (BD +62 deg2114, BD +62 deg 2152, and BD +62 deg 2156) are identified as members ofthis association, while two more (BD +64 deg 1714 and BD +64 deg 1717)are classified as possible members. It is noted that intrinsic colorsand absolute magnitudes of member stars are consistent with thehypothesis of Blaauw (1964) and Garmany (1973) of the existence of twosubgroups with different evolutionary phases.
ICCD speckle observations of binary stars. IV - Measurements during 1986-1988 from the Kitt Peak 4 M telescope One thousand five hundred and fifty measurements of 1006 binary starsystems observed mostly during 1986 through mid-1988 by means of speckleinterferometry with the KPNO 4-m telescope are presented. Twenty-onesystems are directly resolved for the first time, including newcomponents to the cool supergiant Alpha Her A and the Pleiades shellstar Pleione. A continuing survey of The Bright Star Catalogue yieldedeight new binaries from 293 bright stars observed. Corrections tospeckle measures from the GSU/CHARA ICCD speckle camera previouslypublished are presented and discussed.
