- ID:
- ivo://CDS.VizieR/J/ApJ/483/826
- Title:
- BVI CCD photometry of Berkeley 17
- Short Name:
- J/ApJ/483/826
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Faint magnitude BVI CCD photometry of the central region of the old open cluster Berkeley 17 (Be 17) has been undertaken to investigate the claim that it is the oldest open cluster yet discovered (Phelps, Janes, & Montgomery, 1994AJ....107.1079P). This study reveals Be 17 to have a metallicity -0.30<=[Fe/H]<=0.00; a reddening 0.52<=E(B-V)<=0.68 or 0.61<=E(V-I)<=0.71; a distance modulus, (m-M)_0_=12.15+/-0.10, corresponding to a distance of 2.7+/-0.1kpc; a diameter of ~10pc; a minimum mass of 400 Msun; and an age of 10-13Gyr. With an adopted age of 12(+1)(-2)Gyr, these results suggest that Be 17 is indeed the oldest open cluster yet discovered. The inferred old age for Be 17 indicates that the cluster is an important one for studies of the differences between open and globular clusters, the transition from the halo/thick disk to the thin disk of the Galaxy, and even for establishing the minimum age of the universe.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/250/683
- Title:
- BVI CCD photometry of NGC 7510
- Short Name:
- J/MNRAS/250/683
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations in B, V and I passbands have been used to generate deep V, (B-V) and V, (V-I) colour-magnitude diagrams for the open cluster NGC 7510. The sample consists of 592 stars reaching down to V=21mag. There appears to be non- uniform extinction over the face of the cluster with the value of colour excess, E(B-V), ranging from 1.0 to 1.3mag. The law of interstellar extinction in the direction of the cluster is found to be normal. A broad main sequence is clearly visible in both colour-magnitude diagrams. From the bluest part of the colour-magnitude diagrams, the true distance modulus to the cluster has been estimated as 12.5+/-0.3mag and an upper limit of 10 Myr has been assigned for the cluster age.
- ID:
- ivo://CDS.VizieR/J/other/NewA/11.262
- Title:
- BVIc photometry in Lynga 11
- Short Name:
- J/other/NewA/11.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained CCD BVI_KC_ photometry down to V~21.5 for the open cluster Lynga 11 and its surrounding field. This previously unstudied object appears to be rich and highly absorbed. A cluster angular radius of 4.5+/-0.5, equivalent to (3.0+/-0.3)pc, is estimated from star counts in 100-pixel a side boxes distributed throughout the whole observed field. Our analysis suggests that Lynga 11 is moderately young and probably of solar metallicity.
- ID:
- ivo://CDS.VizieR/J/AJ/140/677
- Title:
- BVIc photometry of IC 4665
- Short Name:
- J/AJ/140/677
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new, BVIc photometric survey of the young open cluster IC 4665, which improves on previous studies of this young cluster by incorporating a rigorous standardization procedure, thus providing high-fidelity colors and magnitudes for cluster members. We use this new photometric dataset to reevaluate the properties (age and distance) of IC 4665.
- ID:
- ivo://CDS.VizieR/J/PASJ/56/295
- Title:
- BVIc photometry of old open clusters
- Short Name:
- J/PASJ/56/295
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new photometric data for 14 galactic open clusters taken by the 65cm telescope at Gunma Astronomical Observatory. They were in the anti-galactic center region selected from the Catalog of Open Cluster Data (Lynga, 1987, See Cat. <J/A+A/438/1163>). We estimated the parameters of the clusters, i.e., age, metallicity, distance, and reddening, by fitting Padova isochrones to the color-magnitude diagram.
- ID:
- ivo://CDS.VizieR/J/MNRAS/391/1482
- Title:
- BVIc photometry of Trumpler 20
- Short Name:
- J/MNRAS/391/1482
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We show that the open cluster Trumpler 20, contrary to the earlier findings, is actually an old Galactic open cluster. New CCD photometry and high-resolution spectroscopy are used to derive the main parameters of this cluster. At [Fe/H]=-0.11 for a single red giant star, the metallicity is slightly subsolar. The best fit to the colour-magnitude diagrams is achieved using a 1.3-Gyr isochrone with convective overshoot. The cluster appears to have a significant reddening at E(B-V)=0.46 (for B0 spectral type), although for red giants this high reddening yields the colour temperature exceeding the spectroscopic Teff by about 200K. Trumpler 20 is a very rich open cluster, containing at least 700 members brighter than M_V_=+4. It may extend over the field of view available in our study at 20x20arcmin^2^.
- ID:
- ivo://CDS.VizieR/J/A+A/417/945
- Title:
- BVI & JHK photometry of NGC 3960
- Short Name:
- J/A+A/417/945
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a BVI photometric and astrometric catalogue of the open cluster NGC 3960, down to limiting magnitude V~22, obtained from observations taken with the Wide Field Imager camera at the MPG/ESO 2.2m Telescope at La Silla. The photometry of all the stars detected in our field of view has been used to estimate a map of the strong differential reddening affecting this area. Our results indicate that, within the region where the cluster dominates, the E(V-I) values range from 0.21 up to 0.78, with E(V-I)=0.36 (E(B-V)=0.29) at the nominal cluster centroid position; color excesses E(V-I) up to 1 mag have been measured in the external regions of the field of view where field stars dominate. The reddening-corrected color-magnitude diagram (CMD) allows us to conclude that the cluster has an age between 0.9 and 1.4Gyr and a distance modulus of (V-M_V)_0=11.35. Based on observations made with the European Southern Observatory telescopes obtained from the the ESO/ST-ECF Science Archive Facility.
- ID:
- ivo://CDS.VizieR/J/A+AS/114/537
- Title:
- BVI photometric study of NGC 2453
- Short Name:
- J/A+AS/114/537
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations of the open cluster NGC 2453 have been carried out in B, V and I passbands. A total of 356 stars have been observed in a field of about 4'x6' of the sky centred on the cluster. Colour-magnitude diagrams in V, B-V and V, V-I have been generated down to V=20 and for the first time, the unevolved part of the cluster main sequence has been observed. The mean true distance modulus derived from these diagrams is 13.mag 85+/-0.2 yielding a distance of 5.9+/-0.2kpc. A mean age of 25Myr has been derived for the cluster by fitting isochrones. The distance of approximately 6kpc puts the cluster much beyond the planetary nebula NGC 2452 whose largest estimated distance to date is about 3.5kpc. The two are not physically associated.
- 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.
- 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.