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Improvement of Hipparcos Proper Motions in Declination
More than a decade elapsed after the HIPPARCOS ESA mission (ESA 1997)observations have been collected. This first astronomical satellitemission was less than 4 years long so that 1991.25 is the epoch of theHIPPARCOS Catalogue. Many other projects have checked or improvedHIPPARCOS data. Also, a long series of ground - based opticalobservations of some stars included in HIPPARCOS Catalogue, made withPhotographic Zenith Tubes (PZT) are useful for the task of improving theproper motions of these stars. The ARIHIP Catalogue (after ACT, TYCHO -2, FK6, GC+HIP, TYC2+HIP) is a combination of the HIPPARCOS and someground - based data, and the ARIHIP proper motions are more accuratethan the HIPPARCOS ones. Here we present a new step of our procedure ofcalculation; between PZT data we added the HIPPARCOS position withsuitable weight - the point with the coordinates (1991.25, 0ŭ0)in our case. The method was applied to 202 stars observed at RichmondPZTs in the course of a few decades. The result is better proper motionsin declination for these HIPPARCOS stars, and a good agreement withARIHIP proper motions (we found 128 common Richmond and ARIHIP stars tocheck our result). Also, we present the result for other 74 Richmondstars which are not found in ARIHIP.
| Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
MK spectral types are given for about 584 stars in A Supplement to theBright Star Catalogue. These are compared with Hipparcos parallaxes tocheck the reliability of those classifications. The estimated errors are+/-1.2 subtypes, and 10% of the luminosity classes may be wrong.
| Photoelectric measurements of lunar occultation. VI. Further observational results.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78..482D&db_key=AST
| UBV Photometry of 173 PZT Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971PASP...83..177W&db_key=AST
| Observation of Occultations at Skalnaté Pleso Observatory During the Years 1950-1953
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| Observations of Occultations in the Years 1951 and 1952
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Observation and Astrometry data
| Constellation: | Δίδυμοι |
| Right ascension: | 07h02m07.20s |
| Declination: | +25°25'32.2" |
| Apparent magnitude: | 7.03 |
| Distance: | 149.031 parsecs |
| Proper motion RA: | -13.4 |
| Proper motion Dec: | 2.2 |
| B-T magnitude: | 7.182 |
| V-T magnitude: | 7.043 |
Catalogs and designations:
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