A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry
We present in this paper a catalog of reference stars suitable forcalibrating infrared interferometric observations. In the K band,visibilities can be calibrated with a precision of 1% on baselines up to200 meters for the whole sky, and up to 300 meters for some part of thesky. This work, extending to longer baselines a previous catalogcompiled by Bordé et al. (2002, A&A, 393, 183), isparticularl y well adapted to hectometric-class interferometers such asthe Very Large Telescope Interferometer (VLTI, Glindemann et al. 2003,Proc. SPIE, 4838, 89) or the CHARA array (ten Brummelaar et al. 2003,Proc. SPIE, 4838, 69) when one is observing well-resolved, high-surfacebrightness objects (K 8). We use the absolute spectro-photometriccalibration method introduced by Cohen et al. (1999, AJ, 117, 1864) toderive the angular diameters of our new set of 948 G8-M0 calibratorstars extracted from the IRAS, 2MASS and MSX catalogs. Angular stellardiameters range from 0.6 mas to 1.8 mas (median is 1.1 mas) with amedian precision of 1.35%. For both the northern and southernhemispheres, the closest calibrator star is always less than 10°away.
|
Photoelectric Observations of Southern Cepheids in 2001
A total of 2097 photometric observations in the BVIc systemare presented for 117 Cepheids located in the southern hemisphere. Themain purpose of the photometry is to provide new epochs of maximumbrightness for studying Cepheid period changes, as well as to establishcurrent light elements for the Cepheids.
|
Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
|
The Optical Gravitational Lensing Experiment. UBVI Photometry of Stars in Baade's Window
We present UBVI photometry for 8530 stars in Baade's Window obtainedduring the OGLE-II microlensing survey. Among these are over onethousand red clump giants. 1391 of them have photometry with errorssmaller than 0.04, 0.06, 0.12, and 0.20 mag in the I, V, B, and U-band,respectively. We constructed a map of interstellar reddening. Thecorrected colors of the red clump giants: (U-B)_0, (B-V)_0, and (V-I)_0are very well correlated, indicating that a single parameter determinesthe observed spread of their values, reaching almost 2 mag in the(U-B)_0. It seems most likely that heavy element content is the dominantparameter, but it is possible that another parameter: the age (or mass)of a star moves it along the same trajectory in the color-color diagramas the metallicity. The current ambiguity can be resolved with spectralanalysis, and our catalog may be useful as a finding list of red clumpgiants. We point out that these K giants are more suitable for a fairdetermination of the distribution of metallicity than brighter M giants.We also present a compilation of UBVI data for 308 red clump giants nearthe Sun, for which Hipparcos parallaxes are more accurate than 10%.Spectral analysis of their metallicity may provide information about thelocal metallicity distribution as well as the extent to which mass (age)of these stars affects their colors. It is remarkable that in spite of anumber of problems, stellar models agree with observations at the0.1-0.2 mag level, making red clump giants not only the best calibratedbut also the best understood standard candle.
|
Study of Neglected Variable Stars Classified as Type II Cepheids
Four variable stars classified as Type II Cepheids have been studiedpartly based on new photometry and the Hipparcos photometric data. Thecorrect period is derived for V341 Ara and NW Pav and it is pointed outthat RR Mic and V1711 Sgr do not belong to Type II Cepheids, insteadthey may be semi-regular variables. The cycle length of theirvariability is also determined.
|
Li-rich giants: A survey based on IRAS colours
In a previous work we studied the IRAS colours of known Li-rich redgiants and showed that they have flux ratiosF12/F25 and F25/F60 in welldefined ranges. By using this result as a selection criterion, weprepared a list of 280 IRAS Point Source candidates to be Li-rich giantstars. Up to the present we have obtained spectra for 57% of our targetlist. We identified five stars showing a strong LiI 670.079 nm line andsix ones with a Li line of medium strength. Most of the candidates showfeatures typical of normal giants having circumstellar dust, asindicated by their IRAS colours. Observations collected at theLaboratorio Nacional de Astrofisica - LNA, Brazil; Observatoire de HauteProvence - OHP, France; European Southern Observatory - ESO, Chile.
|
The Southern Vilnius Photometric System. IV - The E region standard stars
This paper is the fourth in a series on the extension of the Vilniusphotometric system to the Southern Hemisphere. Observations were made of60 stars in the Harvard Standard E regions to increase a set of standardstars.
|
The Southern Vilnius Photometric System. III. Observations of E and F Harvard Standard Regions, 47 TUC and Some Metal-Deficient Stars
The results of photoelectric photometry in the Vilnius system of 101southern stars in the areas E1--E4, E8, E9 and F1 as well as of somemetal deficient stars are presented. Photometrically determined spectraltypes and luminosity classes of these stars are also given.
|
Secondary standards for H-beta photometry in the Southern Hemisphere (second series).
Not Available
|
UBV (RI)c standard stars in the E- and F-regions and in the Magellanic Clouds - a revised catalogue.
Not Available
|
Secondary standards for the Stromgren UVBY system
Observations of 158 E region stars have been made in the Stromgrensystem, using the 46-cm reflector at Cape Town. They are mostly brighterthan eighth magnitude and are intended for use as secondary standardsfor the four-color system. The E region relative zero points are definedwith a precision of + or - 0.001 mag, and the internal standard errorsof the colors life between + or - 0.001 and + or - 0.002 mag.
|
UBV photometry of short period cepheids
613 UBV observations of 15 pulsating variables collected on the 1 mreflector at ESO, La Silla, Chile are reported. The variables observedhave periods between one and three days.
|
A search for periodic variability of normal A-type stars
Detailed UBV measurements are presented for seventeen A-type stars, notclassified as peculiar, together with two peculiar A-type stars forcomparison. The results indicate that measurable variation is a rathercommon phenomenon among A-type stars.
|
UBV photometry of E region standard stars of intermediate brightness
Photometry data are given for 335 stars in the nine E regions.Observations were made using a photometer and filters on the 47 cmreflector at Cape Town. The stellar dispersions are summarized. Data arepresented in tabular form.
|
Photoelectric standards of intermediate brightness in the E-regions. I. UBV photometry.
Not Available
|
Photometric standard stars for the UBV and (RI)KC systems.
Not Available
|
Fainter Standards for VRI Photometry in the E Regions
Not Available
|
VRI Photometry of E and F Region Stars [errata: 1978MNSSA..37...35C & 1980MNSSA..39...32C]
Not Available
|
Photoelectric UBV standard sequences in neighbouring parts of the clusters NGC 6256, 6304, 6638 - integrated photometry of NGC 4590, 6256, 6304, 6401, 6638.
Abstract image available at:http://adsabs.harvard.edu/abs/1976A&AS...25..281B
|
Six UBV photoelectric sequences in VELA (l=257 degres to 281 degres.).
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...19...45D&db_key=AST
|
Spectrographic and photometric observations of supergiants and foreground stars in the direction of the Large Magellanic Cloud
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972A&AS....6..249A&db_key=AST
|
Strong-Cyanogen Stars: Photometry and Kinematics
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...165..561J&db_key=AST
|
Standard magnitudes in the E regions.
Not Available
|
