- ID:
- ivo://CDS.VizieR/J/MNRAS/377/1737
- Title:
- BVI photometry of NGC 2489
- Short Name:
- J/MNRAS/377/1737
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD BVI photometry for the southern open cluster NGC 2489 and its surrounding field. The sample consists of 2182 stars measured in an area of 13.6'x13.6', extending down to V~21.5. These data are supplemented with CORAVEL radial-velocity observations for seven red giant candidates. A cluster angular radius of 6.7+/-0.6', equivalent to 3.5+/-0.3pc, is estimated from star counts carried out inside and outside the cluster region. The comparison of the cluster colour-magnitude diagrams with isochrones of the Padova group yields E(B-V)=0.30+/-0.05, E(V-I)=0.40+/-0.05 and V-MV=12.20+/-0.25 for logt=8.70 (t=500^+130^_-100_Myr) and Z=0.019. NGC 2489 is then located at 1.8+/-0.3kpc from the Sun and 25pc below the Galactic plane. The analysis of the kinematical data allowed us to confirm cluster membership for six red giants, one of them being a spectroscopic binary. A mean radial velocity of 38.13+/-0.33km/s was derived for the cluster red giants. The properties of a sample of open clusters aligned along the line of sight of NGC 2489 are examined.
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- ID:
- ivo://CDS.VizieR/J/A+AS/145/365
- Title:
- BVI photometry of NGC 7790
- Short Name:
- J/A+AS/145/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD photometry of the northern open star cluster NGC 7790 has been carried out in BVI photometric passbands down to V~21mag for 1150 stars of which for ~700 stars, the data is obtained for the first time. We derive the most reliable parameters for this cluster using all the available photometric, spectroscopic and proper motion data. The interstellar extinction over the cluster area is uniform and normal with E(B-V)=0.51+/-0.03mag. We determine a distance of 3.3+/-0.23Kpc to the cluster. The theoretical isochrone fittings to the Cepheid variables as well as the evolved part of the main-sequence near turn-off point indicate that the cluster is 120+/-20Myr old. We estimate the cluster radius to be 3.7' using radial stellar density profile. Both the distance and age determined using period luminosity/age relations for the Cepheid variables are consistent with their membership of the cluster. This unique opportunity has therefore been used to refine the zero-point of the period-luminosity relation for the Galactic Cepheids.
- ID:
- ivo://CDS.VizieR/J/MNRAS/367/599
- Title:
- BVI photometry of NGC 5288
- Short Name:
- J/MNRAS/367/599
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present charge-coupled device (CCD) images in the Johnson B and V and Kron-Cousins I passbands for the previously unstudied open cluster NGC 5288. The sample consists of 15688 stars reaching down to V~20.5. The cluster appears to have a relatively small but conspicuous nucleus and a low-density extended coronal region.
- ID:
- ivo://CDS.VizieR/J/A+A/381/65
- Title:
- BVI photometry of NGC 2099
- Short Name:
- J/A+A/381/65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CCD observations of the rich open star cluster NGC 2099 and its surrounding field region have been carried out up to a limiting magnitude of V~22mag in B, V and I passbands for the first time. A total of ~12000 stars have been observed in the area of about 24'x24' in the cluster region, as well as ~2180 stars in the ~ 12'x12' area of the field region located ~45' away from the cluster center. The cluster parameters determined by fitting the convective core overshoot isochrones in the V, (B-V) and V, (V-I) diagrams are E(B-V)=0.30+/-0.40mag, distance=1360+/-100pc, age=400Myr and metallicity Z=0.008.
- ID:
- ivo://CDS.VizieR/J/MNRAS/364/179
- Title:
- BVI photometry of 8 open clusters
- Short Name:
- J/MNRAS/364/179
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD BVI photometry is presented for eight previously unstudied star clusters located in the first and fourth Galactic quadrants: AL 1, BH 150, NGC 5764, Lynga 9, Czernik 37, BH 261, Berkeley 80 and King 25. Colour-magnitude diagrams of the cluster regions suggest that several of them (BH 150, Lynga 9, Czernik 37, BH 261 and King 25) are so embedded in the dense stellar population toward the galactic centre that their properties, or even their existence as physical systems, cannot be confirmed. Lynga 9, BH 261 and King 25 appear to be slight enhancements of dense star fields, BH 150 is probably just a single bright star in a dense field and Czernik 37 may be a sparse, but real cluster superimposed on the galactic bulge population. We derive preliminary estimates of the physical parameters for the remaining clusters. AL 1 appears to be an intermediate-age cluster beyond the solar circle on the far side of the galaxy and the final two clusters, NGC 5764 and Berkeley 80, are also of intermediate age but located inside the solar ring. This set of clusters highlights the difficulties inherent in studying the stellar populations toward the inner regions of the galaxy.
- ID:
- ivo://CDS.VizieR/J/MNRAS/360/655
- Title:
- BVI photometry of 3 open clusters
- Short Name:
- J/MNRAS/360/655
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on BVI CCD photometry to V=22.0 for three fields centred on the region of the Galactic star clusters Ruprecht 4, Ruprecht 7 and Pismis 15 and on three displaced control fields.
- ID:
- ivo://CDS.VizieR/J/A+A/370/931
- Title:
- BVI photometry of 4 open clusters
- Short Name:
- J/A+A/370/931
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CCD observations in the B, V and I passbands have been used to generate colour-magnitude diagrams reaching down to V~19mag for two slightly characterized (Melotte 105 and Hogg 15) and two almost unstudied (Pismis 21 and Ruprecht 140) open clusters. The sample consists of about 1300 stars observed in fields of about 4'x4'. Our analysis shows that neither Pismis 21 nor Ruprecht 140 are genuine open clusters since no clear main sequences or other meaningful features can be seen in their colour-magnitude diagrams. Melotte 105 and Hogg 15 are open clusters affected by E(B-V)=0.42+/-0.03 and 0.95+/-0.05, respectively. Their distances to the Sun have been estimated as 2.2+/-0.3 and 2.6+/-0.08kpc, respectively, while the corresponding ages estimated from empirical isochrones fitted to the Main Sequence cluster members are ~350Myr and 300Myr, respectively. The present data are not consistent with the membership of the WN6 star HDE 311884 to Hogg 15.
- 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.
- ID:
- ivo://CDS.VizieR/J/A+AS/121/455
- Title:
- BVI photometry of stars in Berkeley 18
- Short Name:
- J/A+AS/121/455
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD BVI photometry for Berkeley 18, a rich open cluster located in the Galactic anticenter. The cluster age is similar to, or marginally lower than age of M 67. Its distance is estimated at 5.8kpc and the reddening E(B-V) is probably higher than 0.46. Our data indicate that Be 18 is one of the most populous objects in the whole sample of known galactic open clusters. The angular diameter of the cluster is estimated at 26arcmin, which corresponds to a linear size of about 44pc. The horizontal branch of Be 18 exhibits a large width in comparison with other old open clusters.
- 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.
