- ID:
- ivo://CDS.VizieR/J/A+AS/119/191
- Title:
- CCD BVI photometry in NGC 5927
- Short Name:
- J/A+AS/119/191
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present for the globular cluster NGC 5927 the first multicolor CCD photometry that reaches below the cluster's main sequence turnoff. The turnoff is located approximately at V_TO_=20.1mag, (B-V)_TO_=1.18mag, (V-I)_TO_=1.30mag. There is a hint of horizontal branch morphology variations with distance from the cluster center. Using the isochrones of VandenBerg & Bell (1985ApJS...58..561V), we derive the cluster age to be about 15Gyr.
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- ID:
- ivo://CDS.VizieR/J/ApJ/608/243
- Title:
- CCD BVI photometry of M12 stars
- Short Name:
- J/ApJ/608/243
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observations were done on the nights of UT dates 1995 May 6 and 9 by using the Kitt Peak National Observatory (KPNO) 0.9 m telescope. The file contains BVI data of the globular cluster M12. All frames were taken using a 2048x2048 pixel CCD with pixels covering 0.68 arcseconds on a side, for a total field of approximately 23.2 arcminutes on a side. The data were calibrated against Stetson (2000PASP..112..925S) standard stars.
- ID:
- ivo://CDS.VizieR/J/A+A/379/453
- Title:
- CCD BVI photometry of 5 open cluster candidates
- Short Name:
- J/A+A/379/453
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD BVI observations obtained for 1759 stars in 4'x4' regions around the unstudied southern stellar aggregates Ruprecht 103, 124, 129, 146 and 166, which are described as open clusters in several catalogues. Our analysis shows that none of these stellar groups are genuine open clusters since no clear main sequences or other meaningful features can be seen in their colour-magnitude diagrams. Star counts carried out within and outside the cluster candidate fields not only support these results but also show that the studied objects do not appear to be candidate late stages of star cluster dynamical evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/365/110
- Title:
- CCD BVI photometry of 3 open clusters
- Short Name:
- J/MNRAS/365/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BVI photometry for poorly known southern hemisphere open clusters: NGC 2425, Haffner 10 and Czernik 29. We have calculated the density profile and established the number of stars in each cluster. The colour-magnitude diagrams of the objects show a well-defined main sequence. However, the red giant clump is present only in NGC 2425 and Haffner 10. For these two clusters we estimated the age as 2.5+/-0.5Gyr assuming metallicity of Z=0.008. The apparent distance moduli are in the ranges 13.2<(m-M)_V<13.6 and 14.3<(m-M)_V<14.7, while heliocentric distances are estimated to be 2.9<d<3.8kpc and 3.1<d<4.3kpc, respectively for NGC 2425 and Haffner 10. The angular separation of 2.4deg (150pc at mean distance) may indicate a common origin of the two clusters.
- ID:
- ivo://CDS.VizieR/J/A+AS/133/25
- Title:
- CCD BVI photometry of Trumpler 5
- Short Name:
- J/A+AS/133/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BVI data for stars from the field of the old open cluster Tr 5 are given
- ID:
- ivo://CDS.VizieR/J/AJ/96/1632
- Title:
- CCD BV photometry in M55
- Short Name:
- J/AJ/96/1632
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new CCD photometry for the globular cluster M55 that extends well below the main-sequence turnoff. Combining these new data with previously published photographic photometry of cluster giants and horizontal-branch stars yields a high-quality composite color-magnitude diagram (CMD). A comparison of the latter with recent CMDs for M68 and NGC 6752-two clusters whose metallicities bracket that of M55-suggests (1) that the reddening to M55 may be as high as E(B-V)=0.14mag, and (2) that all three systems have similar ages. In particular, if the apparent distance modulus to M55 is (m-M)_V_=14.10mag, then isochrones for Y=0.24 and high [O/Fe] would suggest an age of ~14Gyr. Very encouraging agreement of the observations with theoretical predictions is found.
- ID:
- ivo://CDS.VizieR/J/AJ/127/958
- Title:
- CCD BV photometry on Omega Cen
- Short Name:
- J/AJ/127/958
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present wide-field and high-precision BV and Ca and Stroemgren by photometry of {omega} Centauri, which represents one of the most extensive photometric surveys to date for this cluster. The member stars of {omega} Cen are well discriminated from foreground Galactic field stars in the hk[=(Ca-b)-(b-y)] versus b-y diagram. The resulting "cleaned" color-magnitude diagram (CMD) has allowed us to obtain an accurate distribution of the red horizontal-branch (HB) and the asymptotic giant branch stars.
- ID:
- ivo://CDS.VizieR/J/A+A/462/591
- Title:
- CCD {Delta}a-photometry of 8 open clusters
- Short Name:
- J/A+A/462/591
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We continue our survey of magnetic chemically peculiar (CP2) stars in galactic open clusters to shed more light on their origin and evolution. To study the group of CP2 stars, it is essential to find these objects in different galactic environments and at a wide range of evolutionary stages. The knowledge of open cluster ages and metallicities can help for finding a correlation between these parameters and the (non-)presence of peculiarities, which has to be taken into account in stellar evolution models. ************************************************************************** * * * Sorry, but the author(s) never supplied the tabular material * * announced in the paper * * * **************************************************************************
- ID:
- ivo://CDS.VizieR/J/A+A/373/153
- Title:
- CCD {Delta}a-photometry of 5 open clusters
- Short Name:
- J/A+A/373/153
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High accurate photometric data in the three filter, narrow band Delta a-system for five open clusters (NGC 2489, NGC 2567, NGC 2658, NGC 5281 and NGC 6208) are presented permitting one to detect apparent chemically peculiar stars. The ages and distances are wide spread to improve the statistics of peculiar stars in our Milky Way. A total of 235 stars within these clusters have been observed. We have detected ten apparent peculiar objects (six with significant positive and four with negative {Delta}a-values) in four open clusters. Although three of them within the boundaries of NGC 2567 are probably not members of this cluster. Since no Stromgren uvbybeta data are available from the literature, Johnson UB-Vphotometry was used to test and calibrate our photometric data. The results from a comparison of both systems are excellent. The tables presented here include all photometric observations of these five clusters. For a description of the {Delta}a photometric system, see e.g. <GCPD/75>
- ID:
- ivo://CDS.VizieR/J/A+A/395/823
- Title:
- CCD {Delta}a-photometry of 5 open clusters
- Short Name:
- J/A+A/395/823
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The time scale on which chemical peculiarity in upper main sequence stars begins is unknown. Results from the Hipparcos measurements indicate that the classical chemically peculiar (CP) stars occupy the whole area from the zero age main sequence to the terminal age main sequence. Hubrig et al. (2000ApJ...539..352H) reported that the magnetic fields appear only in stars that have already completed at least approximately 30% of their main sequence life time. Previous observations in the very young Orion OB1 and Scorpio Centaurus associations reveal a percentage of chemically peculiar stars that is significantly smaller (less than 5%) than that of the galactic field (up to 25%). This already indicates that the phenomenon needs at least several Myr to appear. Since no further observations have been published since then, we have observed the five very young (1Myr<Age<25Myr) open clusters Collinder 272, Pismis 20, Lynga 14, NGC 6396 and NGC 6611. Photometry from 250 CCD frames in the three filter Delta a-system results in very low detection limits (0.008 to 0.015mag). We find no single photometrically chemically peculiar candidate in approximately 460 observed cluster members in the five program clusters. From the number of observed objects we deduce upper limits between 0.6% and 2.4% for the incidence of CP stars for the five observed aggregates.The tables presented here include all photometric observations of these five clusters. For a description of the (Delta a) photometric system, see e.g. <GCPD/75>: a = g2 - (g1+y)/2 g1 and g2 centered at 502 and 524nm.
