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- ID:
- ivo://CDS.VizieR/J/ApJ/628/729
- Title:
- CCD BVIc photometry of M10 stars
- Short Name:
- J/ApJ/628/729
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Observations of the globular cluster M10 were taken at the Kitt Peak National Observatory (KPNO) 0.9 m telescope on the nights of UT dates 1995 May 6 and 9 using BVI filters. 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. Additional high-resolution images were taken at the 3.6 m Canada-France-Hawaii Telescope (CFHT) on the night of UT date 1993 April 13 in BI filters. These observations used a 1200x1200 pixel CCD with pixels covering 0.11 arcseconds on a side, for a total field 2.2 arcminutes on a side, roughly centered on the cluster core. These data were calibrated against the KPNO data.
- 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.
- 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
2818. CCD BV photometry in M55
- 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/620/A137
- Title:
- CCD B,V,R,I,Ha photometry of 3C120
- Short Name:
- J/A+A/620/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At the Universitaetssternwarte Bochum near Cerro Armazones we have monitored the Seyfert-1 galaxy 3C 120 between September 2014 and March 2015 in BVRI and a narrow band filter covering the redshifted H{alpha} line; in addition we obtained a single con-temporary spectrum with FAST at Mt. Hopkins. Compared to earlier epochs 3C 120 is about a factor of three brighter, allowing us to study the shape of the broad line region (BLR) and the dust torus in a high luminosity phase. The analysis of the light curves yields that the dust echo is rather sharp and symmetric in contrast to the more complex broad H{alpha} BLR echo. We investigate how far this supports an optically thick bowl-shaped BLR and dust torus geometry as proposed by Kawaguchi & Mori (2010ApJ...724L.183K) and Goad et al. (2012MNRAS.426.3086G). The comparison with several parameterizations of these models supports the following geometry: the BLR clouds lie inside the bowl closely above the bowl rim, up to a half covering angle 0{deg}<theta<40{deg} (measured against the equatorial plane). Then the BLR is spread over many isodelay surfaces, yielding a smeared and structured echo as observed. Furthermore, if the BLR clouds shield the bottom of the bowl rim against radiation from the nucleus, the hot dust emission comes essentially from the top edge of the bowl (40{deg}<theta< 45{deg}). Then, for small inclinations as for 3C120, the top dust edge forms a ring which largely coincides with a narrow range of isodelay surfaces, yielding the observed sharp dust echo. The scale height of the BLR increases with radial distance from the black hole. This leads to luminosity dependent foreshortening effects of the lag. We discuss implications and possible corrections of the foreshortening for the black hole mass determination and consequences for the lag (size) - luminosity relationships and the difference to interferometric torus sizes.
