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The Nainital-Cape Survey. III. A search for pulsational variability in chemically peculiar stars
Context: The Nainital-Cape survey is a dedicated research programme tosearch for and study the pulsational variability in chemically peculiarstars in the Northern Hemisphere. Aims: The aim of thesurvey is to search for such chemically peculiar stars that arepulsationally unstable. Methods: The observations of thesample stars were carried out in high-speed photometric mode using athree-channel fast photometer attached to the 1.04-m Sampurnanandtelescope at ARIES. Results: The new photometricobservations confirmed that the pulsational period of star HD 25515 is2.78-hrs. The repeated time-series observations of HD 113878 and HD118660 revealed that previously known frequencies are indeed present inthe new data sets. We have estimated the distances, absolute magnitudes,effective temperatures and luminosities of these stars. Their positionsin the H-R diagram indicate that HD 25515 and HD 118660 lie near themain-sequence while HD 113878 is an evolved star. We also present acatalogue of 61 stars classified as null results, along with thecorresponding 87 frequency spectra taken from 2002-2008. A statisticalanalysis of these null results shows, by comparison with past data, thatthe power of the noise in the light curves has slightly increased duringthe last few years.
| Pulkovo compilation of radial velocities for 35495 stars in a common system.
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| Effective temperature scale and bolometric corrections from 2MASS photometry
We present a method to determine effective temperatures, angularsemi-diameters and bolometric corrections for population I and II FGKtype stars based on V and 2MASS IR photometry. Accurate calibration isaccomplished by using a sample of solar analogues, whose averagetemperature is assumed to be equal to the solar effective temperature of5777 K. By taking into account all possible sources of error we estimateassociated uncertainties to better than 1% in effective temperature andin the range 1.0-2.5% in angular semi-diameter for unreddened stars.Comparison of our new temperatures with other determinations extractedfrom the literature indicates, in general, remarkably good agreement.These results suggest that the effective temperaure scale of FGK starsis currently established with an accuracy better than 0.5%-1%. Theapplication of the method to a sample of 10 999 dwarfs in the Hipparcoscatalogue allows us to define temperature and bolometric correction (Kband) calibrations as a function of (V-K), [m/H] and log g. Bolometriccorrections in the V and K bands as a function of T_eff, [m/H] and log gare also given. We provide effective temperatures, angularsemi-diameters, radii and bolometric corrections in the V and K bandsfor the 10 999 FGK stars in our sample with the correspondinguncertainties.
| Radial velocities. Measurements of 2800 B2-F5 stars for HIPPARCOS
Radial velocities have been determined for a sample of 2930 B2-F5 stars,95% observed by the Hipparcos satellite in the north hemisphere and 80%without reliable radial velocity up to now. Observations were obtainedat the Observatoire de Haute Provence with a dispersion of 80Ä,mm(-1) with the aim of studying stellar and galactic dynamics.Radial velocities have been measured by correlation with templates ofthe same spectral class. The mean obtained precision is 3.0 km s(-1)with three observations. A new MK spectral classification is estimatedfor all stars. Based on observations made at the Haute ProvenceObservatory, France and on data from The Hipparcos Catalogue, ESA.Tables 4, 5 and 6 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr or viahttp://cdsweb.u-strasbg.fr/Abstract.htm
| Lists of photometric AM candidates
The Geneva photometric m parameter (Nicolet and Cramer, 1982) is used inorder to select Am photometric candidates from the Rufener (1981)catalogue. Two lists are given, the first containing field stars and thesecond cluster stars. According to the photometric criteria thediffusion process probably responsible for the Am phenomenon takes placerather quickly as Am candidates are present in young clusters. It isconfirmed that the phenomenon is enhanced by low rotational velocity andhigh metallicity. The age seems to slightly affect the Am phenomenon.
| Properties of AM stars in the Geneva photometric system
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1980A&A....92..289H&db_key=AST
| Multicolor photometry of metallic-line stars. III. A photometric catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974RMxAA...1..175M&db_key=AST
| Slit Spectra of Some Peculiar and Metallic-Line A Stars
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| Takýmyýldýz: | Vasak |
| Sað Açýklýk: | 06h20m04.34s |
| Yükselim: | +56°55'31.4" |
| Görünürdeki Parlaklýk: | 8.854 |
| Uzaklýk: | 340.136 parsek |
| özdevim Sað Açýklýk: | -4.8 |
| özdevim Yükselim: | 1.6 |
| B-T magnitude: | 9.238 |
| V-T magnitude: | 8.886 |
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