- ID:
- ivo://CDS.VizieR/J/MNRAS/371/1301
- Title:
- BVI photometry of six old open clusters
- Short Name:
- J/MNRAS/371/1301
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper, we present the first BVI CCD photometry of six overlooked old open clusters (Berkeley 44, NGC 6827, Berkeley 52, Berkeley 56, Skiff 1 and Berkeley 5) and derive estimates of their fundamental parameters by using isochrones from the Padova library. We found that all the clusters are older than the Hyades, with ages ranging from 0.8Gyr (NGC 6827 and Berkeley 5) to 4.0Gyr (Berkeley 56). The latter is one of the old open clusters with the largest heliocentric distance.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/756/L32
- Title:
- BVI photometry of the SMC star cluster ESO 51-SC09
- Short Name:
- J/ApJ/756/L32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results on the age and metallicity estimates of the astonishingly unstudied Small Magellanic Cloud (SMC) cluster (ESO 51-SC09), from CCD BVI photometry obtained at the ESO NTT with the EMMI attached. ESO 51-SC09 turns out to be a relatively small cluster (FWHM=10+/-1pc) located ~4{deg} northward from the galaxy center. We report for the first time a mean cluster age of 7.0+/-1.3Gyr and a mean cluster metallicity of [Fe/H]=-1.00+/-0.15 dex, concluding that ESO 51-SC09 belongs to the group of the oldest SMC clusters. We found that the cluster is projected onto an older (age~10-13Gyr) and more metal-poor ([Fe/H]=-1.3+/-0.2 dex) dominant field stellar population, so that the cluster could have reached its current location because of its orbital motion.
- ID:
- ivo://CDS.VizieR/J/A+A/388/179
- Title:
- BVI photometry of two open clusters
- Short Name:
- J/A+A/388/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of CCD BVI Johnson-Cousins photometry down to V~19mag in the regions of the unstudied stellar groups Pismis 23 and BH 222, both projected close to the direction towards the Galactic centre. We measured V magnitude and B-V and V-I colours for a total of 928 stars in fields of about 4'x4'.
- ID:
- ivo://CDS.VizieR/J/AJ/121/870
- Title:
- BVI photometry of Variables in M33
- Short Name:
- J/AJ/121/870
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The DIRECT project aims to determine direct distances to two important galaxies in the cosmological distance ladder - M31 and M33 - using detached eclipsing binaries (DEBs) and Cepheids. We present the results of the first large-scale CCD-based search for variables in M33. We have observed two fields located in the central region of M33 for a total of 95 nights on the F. L. Whipple Observatory 1.2 m telescope and 36 nights on the Michigan-Dartmouth-MIT 1.3 m telescope. We have found a total of 544 variables, including 251 Cepheids and 47 eclipsing binaries. The catalog of variables is available on-line, along with finding charts and BVI light curve data (consisting of 8.2x10^4^ individual measurements). The complete set of CCD frames is available upon request.
- ID:
- ivo://CDS.VizieR/J/A+A/466/181
- Title:
- BVI photometry of Whiting 1
- Short Name:
- J/A+A/466/181
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recently Carraro (2005ApJ...621L..61C) drew attention to the remarkable star cluster Whiting 1, showing that it lies at about 40kpc from the Sun and is therefore unquestionably a member of the Galactic halo (l=-60.6{deg}). Its Color Magnitude Diagram (CMD) indicated that Whiting 1 is very young (~5Gyrs) for a globular cluster. It is highly likely that Whiting 1 is originated in a dwarf galaxy that has since been disrupted by the Milky Way. The main purpose of the present study is to better constrain the properties of Whiting 1, and assess whether it belongs to a stellar stream from the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph). Deep CCD photometry in the BVI pass-band obtained with the VLT is used to improve the quality of the CMD, and provide more solid estimates of the cluster distance and age, while high resolution spectra of three evolved stars obtained at Magellan is used to derive the cluster kinematics and analyze its possible membership to the Sgr dSph. We demonstrate that - independently on the Halo model employed - Whiting 1 is part of the trailing stream of the Sgr dSph. We derive a new age estimate of 6.5^+1.0^_-0.5_Gyr, and a smaller heliocentric distance of 29.4^+1.8^_-2.0_kpc. The number of globular clusters confirmed to be members of Sgr dSph is now 6. Among these clusters, Whiting 1 is particularly interesting, being the youngest and one of the most metal rich. The existence of Whiting 1 shows how the Sgr dSph was able to form star clusters for a period at least of 6Gyr.
- ID:
- ivo://CDS.VizieR/J/A+A/360/529
- Title:
- BVI photometry of 4 young open clusters
- Short Name:
- J/A+A/360/529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD observations in the B, V, and I passbands obtained for stars in the fields of the open clusters Pismis 22, NGC 6178, NGC 6216, and Ruprecht 130, projected not far from the Galactic centre (|l|<30{deg}, |b|<2{deg}). The sample consists of about 790 stars reaching down to V~18-19mag. From the analysis of the colour magnitude diagrams, we confirmed the physical reality of the clusters and derived their reddening, distance and age. In addition, we obtained flux-calibrated integrated spectra in the range 3500-9200{AA} for the cluster sample. The equivalent widths of the Balmer lines provided us with age estimates, while the comparison with template spectra allowed us to derive both foreground reddening and age. The photometric and spectroscopic results reveal that the four studied objects are young open clusters with ages ranging between 35 and 50Myr. The clusters, located between 1.0kpc and 4.3kpc from the Sun, are affected by different amounts of interstellar visual absorption (0.6=~A_v_=~6.0).
- ID:
- ivo://CDS.VizieR/J/MNRAS/375/1220
- Title:
- BVI photometry of young stars in 10 clusters
- Short Name:
- J/MNRAS/375/1220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected pre-main-sequence (PMS) stars in 12 groups of notional ages ranging from 1 to 35Myr, using heterogeneous membership criteria. Using these members we have constructed empirical isochrones in V, V-I colour-magnitude diagrams. This allows us to identify clearly the gap between the radiative main sequence and the convective PMS (the RC gap). We follow the evolution of this gap with age and show that it can be a useful age indicator for groups less than =15 Myr old. We also observe a reduction in absolute spreads about the sequences with age. Finally, the empirical isochrones allow us to place the groups in order of age, independently of theory. The youngest groups can be collated into three sets of similar ages. The youngest set is the ONC, NGC 6530 and IC 5146 (nominally 1Myr); next Cep OB3b, NGC 2362, Ori and NGC 2264 (nominally 3Myr); and finally Ori and IC 348 (nominally 45Myr). This suggests Cep OB3b is younger than previously thought, and IC 348 older. For IC 348 the stellar rotation rate distribution and fraction of stars with discs imply a younger age than we derive. We suggest this is because of the absence of O-stars in this cluster, whose winds and/or ionizing radiation may be an important factor in the removal of discs in other clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/660/81
- Title:
- BViz photometry of TKRS blue galaxies in GOODS-N
- Short Name:
- J/ApJ/660/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z=1. Based on the detection limits of GOODS, this cannot be explained by incompleteness in low surface brightness galaxies. Number density arguments rule out a pure radius evolution. It can be explained by a radius-dependent decline in B-band luminosity with time.
- ID:
- ivo://CDS.VizieR/J/A+A/567/A1
- Title:
- BVJH photometry of Andrews-Lindsay 1 field
- Short Name:
- J/A+A/567/A1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Andrews-Lindsay 1 is a pertinent open cluster because it may host the planetary nebula (PN) PHR 1315-6555, yet ambiguities linger concerning its fundamental parameters (>50% scatter). New multiband BVJHW_1-4_ photometry for cluster and field stars, in concert with observations of recently discovered classical Cepheids, were used to constrain the reddening and velocity-distance profiles along the sightline. That analysis yielded the following parameters for the cluster: E(J-H)=0.24+/-0.03, d=10.0+/-0.4kpc (d_JH_=9.9+/-0.6kpc, d_BV_=10.1+/-0.5kpc), and log{tau}=8.90+/-0.15. The steep velocity-distance gradient along l~305{deg} indicates that two remote objects sharing spatial and kinematic parameters (i.e., PHR 1315-6555 and Andrews-Lindsay 1) are associated, thus confirming claims that the PN is a cluster member. The new distance for PHR 1315-6555 is among the most precise established yet for a Galactic PN ({sigma}/d=4%).
1770. B3-VLA CSS sample
- ID:
- ivo://CDS.VizieR/J/A+A/426/463
- Title:
- B3-VLA CSS sample
- Short Name:
- J/A+A/426/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of VLBA observations at 6 and 3.6cm for eighteen Compact Steep Spectrum radio sources (CSS) from the B3-VLA CSS sample. In most cases these VLBA images display a "Double/Triple" morphology, and the core is unambiguously detected in seven sources. Multifrequency images allow us to study the spectral properties of the individual source components and to constrain the spectral age. In lobe-dominated sources the radiative ages deduced from the synchrotron theory are in the range of up 5x10^3^ years, if equipartition magnetic field is assumed. Polarized emission is detected at a few percent level for two sources only. They were the only two sources displaying polarized emission in VLA A configuration data, and this implies that beam depolarization is not effective in reducing the integrated fractional polarization for these sources.