- ID:
- ivo://CDS.VizieR/J/A+A/484/609
- Title:
- BVI photometry and proper motions in M67
- Short Name:
- J/A+A/484/609
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The solar-age open cluster M 67 (C0847+ 120, NGC 2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M 67 at fainter magnitudes and their properties are not well-established. Using proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a 34x33arcmin^2^ field centered on the old open cluster M 67. The two-epoch archival observations separated by 4-years and acquired with the Wide-Field Imager at the 2.2m MPG/ ESO telescope were reduced with our new astrometric techniques, as described in the first paper in this series (Anderson et al., 2006A&A...454.1029A). The same observations served to derive calibrated BVI photometry in M 67. Radial velocities were measured using the archival and new spectroscopic data obtained at the VLT.
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- ID:
- ivo://CDS.VizieR/J/A+A/442/917
- Title:
- BVI photometry in Berkeley 73, 75 and 25
- Short Name:
- J/A+A/442/917
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD BVI photometry of the faint open clusters Berkeley 73, Berkeley 75 and Berkeley 25 are presented. The two latter are previously unstudied clusters to our knowledge. While Berkeley 73 is found to be of intermediate-age (about 1.5Gyr old), Berkeley 75 and Berkeley 25 are old clusters, with ages greater than 3.0Gyr. We provide also estimates of the clusters size. All these clusters lie far away from the Galactic Center, at R_GC_>=16kpc, and quite high on the Galactic plane, at |Z_{sun}_|>=1.5kpc. They are therefore important targets to probe the properties of the structure of the Galaxy in this direction, where the Canis Major over-density has been discovered to be located.
- ID:
- ivo://CDS.VizieR/J/MNRAS/344/188
- Title:
- BVI photometry in Fornax cluster galaxies
- Short Name:
- J/MNRAS/344/188
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present BVI photometry of 190 galaxies in the central 4x3deg^2^ region of the Fornax cluster observed with the Michigan Curtis Schmidt Telescope. Results from the Fornax Cluster Spectroscopic Survey (FCSS) and the Flair-II Fornax Surveys have been used to confirm the membership status of galaxies in the Fornax Cluster Catalogue (FCC, Cat. <VII/180>). In our catalogue of 213 member galaxies, 92 (43 per cent) have confirmed radial velocities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/299/1
- Title:
- BVI photometry in four open clusters
- Short Name:
- J/MNRAS/299/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD observations for the distant northern open star clusters Berkeley 81, Berkeley 99, NGC 6603 and NGC 7044 in BVI photometric passbands. A total of 9900 stars have been observed in fields of about 6x6arcmin^2^ of the sky around the clusters. Colour-magnitude diagrams in V, (B-V) and V, (V-I) have been generated down to V=22mag and, for the first time, such diagrams have been produced for the clusters Berkeley 81 and Berkeley 99. The data serve as a base for the study of mass functions and for comparison with theoretical models. Analysis of the radial distribution of stellar surface density indicates that the radius values for Berkeley 81, Berkeley 99, NGC 6603 and NGC 7044 are 2.7, 2.8, 2.8 and 2.2arcmin respectively. By fitting the latest convective core overshooting isochrones to the colour-magnitude diagram and using its morphological features, reddenings, distances and ages of the star clusters have been determined. Broad but well-defined main sequences with stellar evolutionary effects in the brighter stars are clearly visible in colour-magnitude diagrams of all the clusters under study. Some blue stragglers along with well-developed giant branches and red giant clumps are also clearly seen in all of them. The clusters studied here are located at a distance of ~3 kpc, except for Berkeley 99 which is located at a distance of 4.9kpc. Their linear sizes lie between 3.8 and 8.0pc; E(B-V) values range from 0.3 to 1.0mag, while their ages are between 0.5 and 3.2Gyr. Thus the star clusters studied here are of intermediate and high age but are compact and distant objects.
- ID:
- ivo://CDS.VizieR/J/AJ/108/555
- Title:
- BVI photometry in globular cluster M68
- Short Name:
- J/AJ/108/555
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A total of 363 CCD frames in the B, V, and I passbands have been used to study the color-magnitude diagram (CMD) and the variable-star population of the metal-poor galactic globular cluster M68 (NGC 4590, C1236-264). Light curves have been prepared for 40 RR Lyrae variables, five of which are new discoveries, and for two probable SX Phe stars. The RR Lyraes have <V>=15.64+/-0.01, and via several methods E(B-V)=0.07+/-0.01. [Fe/H]=-2.1 is adopted. From a comparison with Sandage's data for M3 (NGC 5272, C1339+286), a period shift of Delta(logP)/Delta([Fe/H])=-0.11+/-0.02 is derived, and the mass-to-light parameter is found to be <A>=1.90. RR Lyrae masses are derived from Fourier fits to the light curves, from the RRd variables, and by comparison with HB (horizontal branch) evolutionary models calculated by Dorman. The light-curve structure agrees qualitatively with recent theoretical models. From short exposures, CMDs have been prepared that are complete from the tip of the red giant branch (RGB) to below the level of the HB, while from the long exposures a CMD to V~23 is provided for 7298 stars more than 158 arcsec distant from the cluster center. The HB is skewed to the blue with the eight bluest stars clearly separated from the remainder of the HB stars. This HB gap is at the identical color to that in M15 (NGC 7078, C2127+119), but M68 lacks the extensive population of the very blue HB stars present in M15. The total number of HB stars is deficient with respect to the RGB population, with the ratio of RGB to HB stars R=0.99. There are several likely blue stragglers identified on CMDs of inner annuli, but near to the cluster center photometric errors scatter stars off the main sequence (MS) into this region. The deep CMDs are in excellent agreement with existing CCD CMDs for M68, with the MS turnoff Delta(V)=3.42+/-0.10mag below the HB. Matching the M68 CMD to that for M15 in the subgiant-MS turnoff region shows that the age of M68 is identical to that for M15 to within +/-0.4Gyr.
2016. BVI photometry in M67
- ID:
- ivo://CDS.VizieR/J/A+A/382/899
- Title:
- BVI photometry in M67
- Short Name:
- J/A+A/382/899
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- File table1 contains various identifications the master list of 977 stars that were included in the photometric variability survey, and which were cross-identified with stars in the study of Fan et al. (1996, Cat. <J/AJ/112/628>). Another 13 stars included in the study, but not cross-identified with the study of Fan et al. can be found in Table 2, which is published in the paper. These 977 stars are those that were included in a roughly square region, 23 arcminutes on each side, centered approximately 5 arcminutes north of the cluster center. The stars have magnitudes in the approximate range 12.5<B<18.5, 12.5<V<18.5, and 12<I<18. File table3 contains BVI photometry for all 990 stars (from Tables 1 and 2) included in the photometric variability study.
- ID:
- ivo://CDS.VizieR/J/AJ/134/825
- Title:
- BVI photometry in M55 (NGC 6809)
- Short Name:
- J/AJ/134/825
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have compiled the asymptotic giant, horizontal, and upper red giant branch (AGB, HB, and RGB) stars in the globular cluster M55 (NGC 6809). Using the star counts and the R-parameter we compute the initial helium abundance Y=0.274+/-0.016.
- ID:
- ivo://CDS.VizieR/J/A+A/462/245
- Title:
- BVI photometry in NGC 6611
- Short Name:
- J/A+A/462/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The observation of young stars with circumstellar disks suggests that the disks are dissipated, starting from the inner region, by the radiation of the central star and eventually by the formation of rocky planetesimals, over a time scale of several million years. It was also shown that strong UV radiation emitted by nearby massive stars can heat a circumstellar disk up to some thousand degrees, inducing the photoevaporation of the gas. This process strongly reduces the dissipation time scale. We study whether there exists a correlation between the spatial distribution of stars with circumstellar disks and the position of massive stars with spectral class earlier than B5, in the open cluster NGC 6611. We created a multiband catalog of the cluster, down to V~23mag, using optical data from a WFI observation at 2.2m of ESO in the BVI bands, the 2MASS public point source catalog and an archival X-ray observation made with CHANDRA/ACIS. We selected the stars with infrared excess (due to the emission of a circumstellar disk) using suitable color indices independent of extinction, and studied their spatial distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/380/478
- Title:
- BVI photometry in NGC 6101
- Short Name:
- J/A+A/380/478
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used HST-WFPC2 and the 1.54 Danish ESO-telescope at La Silla (Chile) to obtain photometry for stars located within 200 arcsec from the center of the cluster NGC 6101. HST-WFPC2 data for 1 field centered on the cluster, have been collected during HST-cycle 6. The resulting V, V-I photometry reach a limiting magnitude of V~25.5. Ground observations have been collected on July 1995. The resulting photometry containing the stars simultaneously detected in the V, B and I filters, is characterized by a limiting magnitude of V~22.5.
- ID:
- ivo://CDS.VizieR/J/AJ/110/638
- Title:
- BVI photometry in NGC 1866
- Short Name:
- J/AJ/110/638
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A photometric sequence consisting of 53 stars measured in the V, B, and I bands has been set up in the vicinity of the rich, young Large Magellanic Cloud cluster, NGC 1866. Many of these stars are relatively isolated and are thus suitable for use as local standard stars for photometric studies of the cluster. Color magnitude diagrams to a limit of V=20.5 for various parts of the 13x13arcmin field, centered on the cluster, show that NGC 1866 is embedded in a mix of populations which includes stars younger than the cluster itself, the dominant 0.5-3Gyr population, plus some very old stars represented by four RR Lyrae variables.