HD 190922

CCD astrometry and instrumental Delta-V photometry of wide visual double stars. III - Differential measurements of often observed southern pairs We present accurate relative positions and instrumental visual (BesselV) magnitude differences of southern wide star components. The meanaccuracy of the angular separation is 0.02 arcsecs, which corresponds to1.5 micron on the CCD chip, and of magnitude difference 0.007mag/exposure. The program pairs are targets of the HIPPARCOS mission andthey have been observed at least four times in the last 150 yrs.
A photometric study of wide visual double stars with significant relative proper motion Photometric observations and uvby H-beta indices of 142 wide visualdouble stars are presented. Calibrations of the indices are used toderive MK class, color excess, absolute magnitude, effectivetemperature, and distance. The results are used to check candidatesdouble stars for the Hipparcos mission for opticity.
UV excess stars and radio sources in the Aquila ring. Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974A&A....31..207I&db_key=AST
Lichtelectrische Untersuchungen eines nahen Sternringes in Aql. Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1969A&A.....3..210I&db_key=AST

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