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Absolute dimensions and apsidal motion of the eccentric binary PT Velorum
High-resolution (λ/dλ ~ 41000) echelle spectra of theeccentric binary system PT Vel were analysed. Precise spectroscopicorbital elements of the system were obtained by means ofcross-correlation technique. According to the solution of radialvelocities with Hipparcos and All Sky Automated Survey-3 (ASAS-3) lightcurves, PT Vel consists of two main-sequence stars with massesM1 = 2.198 +/- 0.016Msolar,M2 = 1.626+/- 0.009Msolar, radii R1 = 2.094 +/-0.020Rsolar,R2 = 1.559 +/- 0.020Rsolarand temperatures Teff1 = 9250 +/- 150 K, Teff2 =7650 +/- 200 K separated from each other by A = 9.74 +/-0.02Rsolar in an orbit inclined . The projected rotationalvelocities of component stars were found to be (v sini)1 = 63+/- 2 and (v sini)2 = 40 +/- 3kms-1 from thecomparison of observed spectra with synthetic spectra which werecalculated using model atmospheres. Our measurements of the projectedrotational velocities indicate that both stars rotate synchronously.Analysis of longitude of periastron values obtained from light-curveanalysis from different photometric sets of this moderately eccentricsystem (e = 0.127 +/- 0.006) has revealed a significant motion of theline of apsides of corresponding to an apsidal motion period of U =182.2 +/- 8.4yr. The contribution from general relativity effects ismoderate (~9 per cent). A comparison with predictions from interiorstructure models shows the real stars to be more concentrated in massthan expected. Comparison of absolute dimensions with theoreticalisochrones yielded an age of the system of 400 +/- 40 Myr.
| A revised catalogue of delta Sct stars
An extensive and up-dated list of delta Sct stars is presented here.More than 500 papers, published during the last few years, have beenrevised and 341 new variables have been added to our last list, sixyears ago. This catalogue is intended to be a comprehensive review onthe observational characteristics of all the delta Sct stars known untilnow, including stars contained in earlier catalogues together with othernew discovered variables, covering information published until January2000. In summary, 636 variables, 1149 references and 182 individualnotes are presented in this new list. Tables 1 and 2 will be accessibleonly in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
| The 73rd Name-List of Variable Stars
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| Nine new Delta Scuti stars
Differential photometry in the V and B wavebands is presented for elevendeltaScuti stars. Nine of the stars were not previously known to bevariable stars. All the stars are bright, being in the Henry Drapercatalogue. Physical characteristics of the stars are estimated frompublished spectroscopy or photometry, and pulsation constants arederived. The recently discovered deltaScuti star II Vir may be alambdaBootis star.
| VBLUW-photometry of stars in small fields around 13 planetary nebulae
Observations of stars in small fields around 13 planetary nebulae, madeusing the Walraven five-channel VBLUW photometer, are presented anddescribed. The fields are found to have a radius of about 0.3 deg. Thefinding charts for the measured stars are given. It is shown that moststars are brighter than mV of about 14 mag and that the photometry hasan accuracy of better than 1 percent, except for stars that are observedwith short test-integrations and for stars fainter than mV of about 14mag. The photometric data for all stars are presented, together with alist of identifications and spectral types.
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| Takýmyýldýz: | Yelken |
| Sað Açýklýk: | 09h11m07.50s |
| Yükselim: | -43°16'11.5" |
| Görünürdeki Parlaklýk: | 7.853 |
| Uzaklýk: | 257.732 parsek |
| özdevim Sað Açýklýk: | -14.5 |
| özdevim Yükselim: | 17.5 |
| B-T magnitude: | 8.238 |
| V-T magnitude: | 7.885 |
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