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Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i
This work is the second part of the set of measurements of v sin i forA-type stars, begun by Royer et al. (\cite{Ror_02a}). Spectra of 249 B8to F2-type stars brighter than V=7 have been collected at Observatoirede Haute-Provence (OHP). Fourier transforms of several line profiles inthe range 4200-4600 Å are used to derive v sin i from thefrequency of the first zero. Statistical analysis of the sampleindicates that measurement error mainly depends on v sin i and thisrelative error of the rotational velocity is found to be about 5% onaverage. The systematic shift with respect to standard values fromSlettebak et al. (\cite{Slk_75}), previously found in the first paper,is here confirmed. Comparisons with data from the literature agree withour findings: v sin i values from Slettebak et al. are underestimatedand the relation between both scales follows a linear law ensuremath vsin inew = 1.03 v sin iold+7.7. Finally, thesedata are combined with those from the previous paper (Royer et al.\cite{Ror_02a}), together with the catalogue of Abt & Morrell(\cite{AbtMol95}). The resulting sample includes some 2150 stars withhomogenized rotational velocities. Based on observations made atObservatoire de Haute Provence (CNRS), France. Tables \ref{results} and\ref{merging} are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.125.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/393/897
| KPNO lunar occultation summary. II
The results from 65 lunar occultation observations between August 1984and July 1986 are discussed. The instrumentation and reductionprocedures used in the study are described. Parameters are given fornine different double/multiple stars and for two stars with measurableangular diameters. Three newly discovered double stars, SAO 77310, SAO79241, and the brighter component of SAO 77837, are examined. Inaddition, a fourth star, the brighter component of SAO 76862, isresolved for the first time.
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Gözlemler ve gökölçümü verileri
| Takýmyýldýz: | Yay |
| Sað Açýklýk: | 18h28m57.24s |
| Yükselim: | -26°35'37.4" |
| Görünürdeki Parlaklýk: | 7.968 |
| Uzaklýk: | 136.612 parsek |
| özdevim Sað Açýklýk: | -4.3 |
| özdevim Yükselim: | -4.9 |
| B-T magnitude: | 8.206 |
| V-T magnitude: | 7.988 |
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