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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.
| Stars Classified as Constant in the General Catalogue of Variable Stars, II
Photometric observations have been made of 36 stars classified as CST orCST: in the General Catalogue of Variable Stars. Six of these stars arefound to vary and three others were deemed possible variables. Of thecertain variables, two (MR Her and TY Sge) are red pulsators, one (V1585Cyg) is a rapid irregular variable, one is apparently a short periodCepheid-strip star (V432 Oph), one is an eclipsing binary (AQ Boo) andone is uncertain type (V351 Cyg). The stars we have observed as MR Herand TY Sge are the same ones which were identified on finding charts inthe discovery papers suggesting that these stars have intervals ofvariability and intervals of quiescence. V432 Oph is of special interestbecause our photometry indicates that it may be either a double modeCepheid or a peculiar long period RR Lyrae star depending on which of acouple of possible periods turns out to be correct. (SECTION: Stars)
| The S201 far-ultraviolet imaging survey. II - A field in Cygnus
Far-ultraviolet imagery of a region in Cygnus, a 20 deg diameter fieldcentered near (1950) R. A. 21 h 31.2 m decl. +37 deg 25 arcmin, wasobtained by the S201 far-ultraviolet camera during the Apollo 16mission. In a 10 minute exposure covering the 1250-1600 A wavelengthrange (effective wavelength 1400 A), 730 star images can be detected,corresponding to a limiting ultraviolet magnitude of about m (1400) =10. Assuming nominal interstellar extinction values in this region nearthe galactic plane, this result corresponds to the detection of A0 Vstars to a distance of 300 pc and of B0 V stars to 1500 pc.Uncertainties in spectral classification and interstellar extinction forindividual objects are probably more significant than calibration ormeasurement errors. Most of the objects detected are identified withstars in the Smithsonian Astrophysical Observatory Star Catalog (1966),or the Catalog of Stellar Identifications (1979) or both, but 87 objectsremain unidentified (or are identified with late-type stars).
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Observation and Astrometry data
| Constellation: | Pegasus |
| Right ascension: | 22h04m08.22s |
| Declination: | +35°45'34.4" |
| Apparent magnitude: | 9.401 |
| Proper motion RA: | -3.8 |
| Proper motion Dec: | -7.1 |
| B-T magnitude: | 9.444 |
| V-T magnitude: | 9.405 |
Catalogs and designations:
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