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22941. ubvy photometry of CR Cas
ID:
ivo://CDS.VizieR/J/A+AS/128/139
Title:
ubvy photometry of CR Cas
Short Name:
J/A+AS/128/139
Date:
21 Oct 2021
Publisher:
CDS
Description:
The table contains the differential magnitudes of CR Cas respect to comparison star SAO35044 indicating the time (Julian Date) a nd magnitudes in Stroemgren filters u, v, b, y
22942. ubvy photometry of LMC/SMC B stars
ID:
ivo://CDS.VizieR/J/A+A/364/455
Title:
ubvy photometry of LMC/SMC B stars
Short Name:
J/A+A/364/455
Date:
21 Oct 2021
Publisher:
CDS
Description:
The individual reddenings for B stars in two fields in the Small Magellanic Cloud (SMC) and two fields in the Large Magellanic Cloud (LMC) are determined by means of Stroemgren uvby CCD photometry. In both LMC fields we find a foreground reddening of E(B-V)=0.085+/-0.02, and for the SMC fields we find E(B-V)=0.070+/-0.02. In addition to the foreground reddening we find contributions from reddening intrinsically in the Clouds up to E(B-V)~0.21. The intrinsic contribution is not correlated with position within our ~6'x4.5' CCD fields but varies in an essentially random way. Unless the reddening is measured for a particular object, it will be uncertain by +/-0.035 (best case, far from the central bars) to more than +/-0.10 (close to the central bars). The Stroemgren uvby photometry has been used to derive metallicities for GK giant stars in the observed fields. Adopting average reddenings we obtain mean metallicities which are consistent with those found from spectroscopic studies of F and G supergiants (Westerlund, 1997, The Magellanic Clouds, Cambridge University Press), but with a considerable scatter in the derived metallicities, from [Fe/H]=~-2.0 to [Fe/H]>0. A significant fraction of the scatter is, however, due to reddening variations rather than being intrinsic. The possible existence of high metallicity stars should be investigated further using spectroscopic methods.
22943. ubvy photometry of 4 magnetic CP stars
ID:
ivo://CDS.VizieR/J/A+A/435/1099
Title:
ubvy photometry of 4 magnetic CP stars
Short Name:
J/A+A/435/1099
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential Stroemgren uvby observations from the Four College Automated Photoelectric Telescope are presented for the magnetic Chemically Peculiar (mCP) stars HD 32633, Aur, 49 Cam, and 3 Hya. We find for over 30 years, these four stars with stable optical region light curves have had constant periods of 6.4300, 3.61868, 4.28679, and 11.305 days, respectively.
22944. ubvy Photometry of magnetic CP stars
ID:
ivo://CDS.VizieR/J/A+AS/103/1
Title:
ubvy Photometry of magnetic CP stars
Short Name:
J/A+AS/103/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope of four magnetic Chemically Peculiar stars are presented. We refined the period of 63 And to 4.1890 days. The period of the sharp-lined Si star HD 192913 is 16.840 days, a value close to, but slightly different from published values. HR 8240, a sharp-lined Si star, is found not to be a photometric variable. Comparison of four color photometry of 108 Aqr by Morrison and Wolff and from the Four College APT indicates that subtle changes in the shapes of the light curves, especially that for u, have occurred suggesting that this star may be precessing.
22945. ubvy Photometry of magnetic CP stars
ID:
ivo://CDS.VizieR/J/A+A/357/548
Title:
ubvy Photometry of magnetic CP stars
Short Name:
J/A+A/357/548
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential Stroemgren uvby photometric observations from the Four College Automated Photoelectric Telescope (FCAPT) are presented for the magnetic CP stars HD 36668, 36 Lyn, HD 86592, and HR 8861. Using the FCAPT values, North's period for HD 36668 is refined to 2.11884 days. The 3.834 day period of Shore et al. (1990ApJ...348..242S) for 36 Lyn, which was found from magnetic field measurements, is confirmed by photometry. The FCAPT observations also support the 2.8867 day period of Babel & North (1997A&A...325..195B) for HD 86592, demonstrate that this star is a large amplitude variable in v (0.13 mag), and show that y varies crudely out of phase from u, v, and b which are in phase with one another. The variability of HR 8861 appears to be correlated with the meridional passages of regions of Si over- and underabundance as found by Piskunov et al. (1994A&A...291..910P)
22946. ubvy photometry of NGC2419
ID:
ivo://CDS.VizieR/J/A+A/581/A72
Title:
ubvy photometry of NGC2419
Short Name:
J/A+A/581/A72
Date:
21 Oct 2021
Publisher:
CDS
Description:
NGC 2419 is a peculiar Galactic globular cluster offset from the others in the size-luminosity diagram, and showing several chemical abundance anomalies. Here, we present Stromgren uvby photometry of the cluster. Using the gravity- and metallicity-sensitive c1 and m1 indices, we identify a sample of likely cluster members extending well beyond the formal tidal radius. The estimated contamination by cluster non-members is only one per cent, making our catalogue ideally suited for spectroscopic follow-up. We derive photometric [Fe/H] of red giants, and depending on which metallicity calibration from the literature we use, we find reasonable to excellent agreement with spectroscopic [Fe/H], both for the cluster mean metallicity and for individual stars. We demonstrate explicitly that the photometric uncertainties are not Gaussian and this must be accounted for in any analysis of the metallicity distribution function.
22947. UCAC2 Catalogue
ID:
ivo://CDS.VizieR/I/289
Title:
UCAC2 Catalogue
Short Name:
I/289
Date:
21 Oct 2021
Publisher:
CDS
Description:
The UCAC2 is the second release of the ongoing UCAC project, designed to observe the entire sky for R magnitudes of about 7.5 to 16. The observed positional errors are about 20 mas for the stars in the 10-14 magnitude range, and about 70 mas at the limiting magnitude of R~16. For up-to-date information on the project, see the UCAC web page at http://ad.usno.navy.mil/ucac/ . This web page will also serve as the location that the UCAC team will post addenda to the UCAC2 catalog. The UCAC2 is a high density, highly accurate, astrometric catalog of 48,330,571 stars covering the sky from -90 to +40 degrees in declination and going up to +52 degrees in some areas. The northern limit is a function of right ascension. Proper motions and photometry are provided for all stars. Positions and proper motions are on the ICRS (International Celestial Reference System) and given at the epoch J2000.0. The UCAC2 has a number of major differences with respect to UCAC1. These differences include: - much larger sky coverage - reduced systematic errors of CCD observations - positions given at a standard epoch (J2000.0) - the addition of several new catalogs for improved proper motions - photometry in the J, H, and K_s bands from the 2MASS project Additional details of the data are found in Sections 3, 4, and 5 of the "readme.txt" file. UCAC2 is the last intermediate data release before the final, all sky catalog will be constructed. Observations will end around mid 2004; the final catalog is expected out in 2005. The UCAC project, observations, and first data release are described in detail in the paper Zacharias et al. AJ 120, 2131 (2000). Versions of that and other related papers are placed on the UCAC Web page (http://ad.usno.navy.mil/ucac/). The paper describing UCAC2 is in preparation (AJ, 2003); some further details can be found in the "readme.txt" file.
22948. UCAC1 Catalogue
ID:
ivo://CDS.VizieR/I/268
Title:
UCAC1 Catalogue
Short Name:
I/268
Date:
21 Oct 2021
Publisher:
CDS
Description:
The UCAC1 is a high density, highly accurate, astrometric catalog of over 27 million stars in the Southern Hemisphere in the magnitude range of about 8 to 16. This version is the first release of an ongoing project to observe the entire sky; for up-to-date information see the Web page at http://ad.usno.navy.mil/ad/ucac/ . The UCAC1 is a preliminary catalog. By avoiding all "problem cases" (see details in the "intro.txt" file) it is not complete. Positions, proper motions and errors are provided, together with approximate magnitudes in the 579-642nm range. The positional precision is about 20 mas for 9 to 14 mag and 70 mas at 16th mag. The errors of the proper motions are very heterogeneous, ranging from 1 to 35 mas/yr. The UCAC is an observational program using the U.S. Naval Observatory Twin Astrograph and a 4kx4k CCD camera, covering just over 1 square degree per frame with a scale of 0.9"/pixel. Observations started in January 1998 at Cerro Tololo Interamerican Observatory (CTIO) and are continuing. This first catalog contains data observed through 07 November 1999 at which time about 80% of the Southern Hemisphere was completed. Full sky coverage is expected by early 2003 after a re-location of the instrument to the Northern Hemisphere planned for early 2001. The UCAC1 is also available on CD-ROM from the US Naval Observatory. Direct request to nz@pisces.usno.navy.mil with UCAC1 in the subject string.
22949. UCAC4 Catalogue
ID:
ivo://CDS.VizieR/I/322A
Title:
UCAC4 Catalogue
Short Name:
I/322A
Date:
21 Oct 2021
Publisher:
CDS
Description:
UCAC4 is a compiled, all-sky star catalog covering mainly the 8 to 16 magnitude range in a single bandpass between V and R. Positional errors are about 15 to 20 mas for stars in the 10 to 14 mag range. Proper motions have been derived for most of the about 113 million stars utilizing about 140 other star catalogs with significant epoch difference to the UCAC CCD observations. These data are supplemented by 2MASS photometric data for about 110 million stars and 5-band (B,V,g,r,i) photometry from the APASS (AAVSO Photometric All-Sky Survey) for over 50 million stars. UCAC4 also contains error estimates and various flags. All bright stars not observed with the astrograph have been added to UCAC4 from a set of Hipparcos and Tycho-2 stars. Thus UCAC4 should be complete from the brightest stars to about R=16, with the source of data indicated in flags. UCAC4 also provides a link to the original Hipparcos star number with additional data such as parallax found on a separate data file included in this release. The proper motions of bright stars are based on about 140 catalogs, including Hipparcos and Tycho, as well as all catalogs used for the Tycho-2 proper motion construction. Proper motions of faint stars are based on re-reductions of early epoch SPM data (-90 to about -20 deg Dec) and NPM (PMM scans of early epoch blue plates) for the remainder of the sky. These early epoch SPM data have also been combined with late epoch SPM data to arrive at proper motions partly independent from UCAC4 (Girard et al. 2011AJ....142...15G, Cat. I/320). The NPM data used in UCAC4 are not published. No Schmidt plate data are used in UCAC4. The unpublished plate measure data obtained by StarScan from the AGK2, the Hamburg Zone Astrograph, the USNO Black Birch Astrograph, and the Lick Astrograph have contributed to considerable improvement in proper motions for stars mainly in the 10 to 14 mag range (down to the UCAC limit for Lick data); however, these data do not cover all sky. Recources permitting, USNO plans to release the individual CCD observations (RA,Dec at epoch of each CCD observations) in the future. Please contact nz@usno.navy.mil if you are interested in obtaining this set of about 50 GB data. We will likely request that interested users provide an external disk drive for the data release.
22950. UCAC3 Catalogue
ID:
ivo://CDS.VizieR/I/315
Title:
UCAC3 Catalogue
Short Name:
I/315
Date:
21 Oct 2021
Publisher:
CDS
Description:
UCAC3 is a compiled, all-sky star catalog covering mainly the 8 to 16 magnitude range in a single bandpass between V and R. Positional errors are about 15 to 20 mas for stars in the 10 to 14 mag range. It is supplemented by proper motions and SuperCosmos and 2MASS photometric data, as well as various flags. The proper motions of bright stars are based on about 140 catalogs, including Hipparcos and Tycho, as well as all catalogs used for the Tycho-2 proper motion construction. Proper motions of faint stars are based on a re-reduction of early epoch SPM data (-90 to -10 deg Dec) plus Schmidt plate data from the SuperCosmos project (down weighted due to systematic errors of order 100 mas). The proper motions of faint stars (R >= 13.5) therefore should be used with caution. The unpublished plate measure data from the AGK2, the Hamburg Zone Astrograph, the USNO Black Birch Astrograph, and the Lick Astrograph have considerably contributed to improve proper motions for stars mainly in the 10 to 14 mag range (down to the UCAC3 limit for Lick data); however, these data do not cover all sky. UCAC3 features a number of major differences with respect to UCAC2: - complete sky coverage - re-reduction of the pixel data with better modeling - double stars are resolved to the limit of the data - significantly improved photometry from CCD data - slightly deeper limiting magnitude with larger number of stars/area - reduced systematic errors of CCD observations - the addition of several new catalogs for improved proper motions - photometry in the B, R, and I bands from the SuperCosmos project - minor planet observations have been sorted out - identification of more high proper motion stars - match with 2MASS extended sources and LEDA galaxies Additional details will be published in the upcoming release paper (Zacharias et al. 2009) and in several technical papers describing details of the reduction procedures and results. For the latest updates see http://www.usno.navy.mil/usno/astrometry . Requests for the data DVD should be sent to ucac3@usno.navy.mil; technical questions can be addressed to nz@usno.navy.mil .

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