- ID:
- ivo://CDS.VizieR/J/A+A/511/A38
- Title:
- Open clusters in third galactic quadrant
- Short Name:
- J/A+A/511/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to determine accurate distances and ages of eight open clusters in order to: (1) assess their possible binarity (2) provide probes to trace the structure of the Third Galactic Quadrant. Cluster reddenings, distances, ages and metallicities are derived from ZAMS and isochrone fits in UBVRI photometric diagrams. Field contamination is reduced by restricting analysis to stars within the cluster limits derived from star counts. Further membership control is done by requiring that stars have consistent positions in several diagrams and by using published spectral types.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/470/3937
- Title:
- 1876 open clusters multimembership catalog
- Short Name:
- J/MNRAS/470/3937
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The main objective of this work is to determine the cluster members of 1876 open clusters, using positions and proper motions of the astrometric fourth United States Naval Observatory (USNO) CCD Astrograph Catalog (UCAC4). For this purpose, we apply three different methods, all based on a Bayesian approach, but with different formulations: a purely parametric method, another completely non-parametric algorithm and a third, recently developed by Sampedro & Alfaro (2016MNRAS.457.3949S), using both formulations at different steps of the whole process. The first and second statistical moments of the members' phase-space subspace, obtained after applying the three methods, are compared for every cluster. Although, on average, the three methods yield similar results, there are also specific differences between them, as well as for some particular clusters. The comparison with other published catalogues shows good agreement. We have also estimated, for the first time, the mean proper motion for a sample of 18 clusters. The results are organized in a single catalogue formed by two main files, one with the most relevant information for each cluster, partially including that in UCAC4, and the other showing the individual membership probabilities for each star in the cluster area. The final catalogue, with an interface design that enables an easy interaction with the user, is available in electronic format at the Stellar Systems Group (SSG-IAA) web site (http://ssg.iaa.es/en/content/sampedro-cluster-catalog).
- ID:
- ivo://CDS.VizieR/J/AJ/105/1822
- Title:
- Open clusters near eta Car
- Short Name:
- J/AJ/105/1822
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Proper motions and photographic photometry have been derived for nearly 600 stars with 7.5 < V < 15.5 in the region of the very young open clusters Tr 14, Tr 16, and Cr 232 based on 26 plates dating from 1893 to 1990. Cluster membership probabilities have been derived from the proper motions and color-magnitude diagrams of probable members of each cluster are presented. In contrast to a few of the previous studies we find all three clusters to lie at the same distance.
- ID:
- ivo://CDS.VizieR/J/A+A/637/A95
- Title:
- 16 open clusters UBVI and Gaia DR2 photometry
- Short Name:
- J/A+A/637/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper has two main objectives: (1) To determine the intrinsic properties of sixteen faint and mostly unstudied open clusters in the poorly known sector of the Galaxy at 270{deg}-300{deg}, to probe the Milky Way structure in future investigations. (2) To address previously reported systematics in Gaia DR2 parallaxes by comparing the cluster distances derived from photometry with those derived from parallaxes. Deep UBVI photometry of 16 open clusters was carried out. Observations were reduced and analyzed in an automatic way using the ASteCA package to get individual distances, reddening, masses, ages and metallicities. Photometric distances were compared to those obtained from a Bayesian analysis of Gaia DR2 parallaxes. Ten out of the sixteen clusters are true or highly probable open clusters. Two of them are quite young and follow the trace of the Carina Arm and the already detected warp. The rest of the clusters are placed in the interarm zone between the Perseus and Carina Arms as expected for older objects. We found that the cluster van den Berg-Hagen 85 is 7.5x10^9^yrs old becoming then one of the oldest open cluster detected in our Galaxy so far. The relationship of these ten clusters with the Galaxy structure in the solar neighborhood is discussed. The comparison of distances from photometry and parallaxes data, in turn, reveals a variable level of disagreement. Various zero point corrections for Gaia DR2 parallax data recently reported were considered for a comparison between photometric and parallax based distances. The results tend to improve with some of these corrections. Photometric distance analysis suggest an average correction of ~+0.026mas (to be added to the parallaxes). The correction may have a more intricate distance dependency, but addressing that level of detail will require a larger cluster sample.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A9
- Title:
- Open star cluster Coma Berenices multi-photometry
- Short Name:
- J/A+A/640/A9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We mainly aim to search for the lithium depletion boundary (LDB) among the sub-stellar population of the open star cluster Coma Berenices. Since the number of brown dwarf candidates in Coma Ber available in the literature is scarce, we carried out a search for additional candidates photometrically using colour-magnitude diagrams combining optical and infrared photometry from the latest public releases of the following large-scale surveys: the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIRT/UKIDSS), the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS), the Sloan Digital Sky Survey (SDSS), and AllWISE. We checked astrometric consistency with cluster membership using Gaia DR2. A search for Li in three new and five previously known brown dwarf candidate cluster members was performed via spectroscopic observations using the OSIRIS instrument at the 10.4m Gran Telescopio de Canarias (GTC). A couple dozen new photometric candidate brown dwarfs located inside the tidal radius of Coma Ber are reported, but none of these are significantly fainter and cooler than previously known members. No LiI resonance doublet at 6707.8{AA} was detected in any of eight Coma Ber targets in the magnitude range J=15-19 and G=20-23 observed with the GTC. Spectral types and radial velocities were derived from the GTC spectra. These values confirm the cluster membership of four L2-L2.5 dwarfs, two of which are new in the literature. The large Li depletion factors found among the four bona fide sub-stellar members in Coma Ber implies that the LDB must be located at spectral type later than L2.5 in this cluster. Using the latest evolutionary models for brown dwarfs, a lower limit of 550Myr on the cluster age is set. This constraint has been combined with other dating methods to obtain an updated age estimate of 780+/-230Myr for the Coma Ber open cluster. Identification of significantly cooler sub-stellar cluster members in Coma Ber awaits the advent of the Euclid wide survey, which should reach a depth of about J=23; this superb sensitivity will make it possible to determine the precise location of the sub-stellar LDB in this cluster and to carry out a complete census of its sub-stellar population.
- ID:
- ivo://CDS.VizieR/J/A+A/369/511
- Title:
- Open star clusters. III. NGC 4103, 5281, 4755
- Short Name:
- J/A+A/369/511
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables 5, 7, and 8 contain the data of the CCD photometry of the three open star clusters. We added the numbering systems of previously published papers to the tables. Table 5 contains the data of NGC 4103 with stellar numbers from Wesselink (1969MNRAS.146..329W); Table 7 the data of NGC 5281 with the numbers of Moffat & Vogt (1973A&AS...10..135M); Table 8 the data of NGC 4755 with the numbering system according to Arp & van Sant (1958AJ.....63..341A). In Tables 12, 13, and 14 we present relative proper motions of the three clusters (in the same sequence). For NGC 4103 the table contains the information of an entire Carte du Ciel field of 2 degrees square, for the other two clusters, a small subfield had to be selected beforehand. The numbers of Arp & van Sant (1958AJ.....63..341A) are encrypted in the following way: Numbers <100 stand for the stars A to Q, the first digit of the numbers >100 represents the quadrant. The two final digits are the running numbers in the notation of Arp & van Sant (1958AJ.....63..341A).
- ID:
- ivo://CDS.VizieR/J/A+A/349/448
- Title:
- Open star clusters. I. NGC 581 (M 103)
- Short Name:
- J/A+A/349/448
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CCD photometry and a proper motion study of the young open star cluster, NGC 581 (M 103). Fitting isochrones to the colour magnitude diagram, we found an age of 16+/-4Myr and a distance of roughly 3kpc for this cluster. The proper motion study identifies 77 stars of V=14.5mag or brighter to be cluster members. We combine membership determination by proper motions and statistical field star subtraction to derive the IMF of the cluster and find a quite steep slope of {Gamma}=-1.80.
- ID:
- ivo://CDS.VizieR/J/MNRAS/482/698
- Title:
- Ophiuchus DIsc Survey Employing ALMA (ODISEA). I.
- Short Name:
- J/MNRAS/482/698
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce the Ophiuchus DIsc Survey Employing ALMA (ODISEA), a project aiming to study the entire population of Spitzer-selected protoplanetary discs in the Ophiuchus Molecular Cloud (~300 objects) from both millimetre continuum and CO isotopologues data. Here we present 1.3mm/230GHz continuum images of 147 targets at 0.2" (28au) resolution and a typical rms of 0.15mJy. We detect a total of 133 discs, including the individual components of 11 binary systems and 1 triple system. 60 of these discs are spatially resolved. We find clear substructures (inner cavities, rings, gaps, and/or spiral arms) in eight of the sources and hints of such structures in another four discs. We construct the disc luminosity function for our targets and perform preliminary comparisons to other regions. A simple conversion between flux and dust mass (adopting standard assumptions) indicates that all discs detected at 1.3mm are massive enough to form one or more rocky planets. In contrast, only ~50 discs (~1/3 of the sample) have enough mass in the form of dust to form the canonical 10M_{Earth}_ core needed to trigger runaway gas accretion and the formation of gas giant planets, although the total mass of solids already incorporated into bodies larger than cm scales is mostly unconstrained. The distribution in continuum disc sizes in our sample is heavily weighted towards compact discs: most detected discs have radii <15au, while only 23 discs (~15% of the targets) have radii >30au.
- ID:
- ivo://CDS.VizieR/J/A+A/583/A124
- Title:
- Ophiuchus r'g'z' photometry and redshifts
- Short Name:
- J/A+A/583/A124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Ophiuchus cluster, at a redshift z=0.0296, is known from X-rays to be one of the most massive nearby clusters, but due to its very low Galactic latitude its optical properties have not been investigated in detail. Aims. We discuss the optical properties of the galaxies in the Ophiuchus cluster, in particular with the aim of understanding better its dynamical properties. We have obtained deep optical imaging in several bands with various telescopes, and applied a sophisticated method to model and subtract the contributions of stars in order to measure galaxy magnitudes as accurately as possible. The colour-magnitude relations obtained show that there are hardly any blue galaxies in Ophiuchus (at least brighter than r'<=19.5), and this is confirmed by the fact that we only detect two galaxies in H{alpha}. We also obtained a number of spectra with ESO-FORS2, that we combined with previously available redshifts. Altogether, we have 152 galaxies with spectroscopic redshifts in the 0.02<=z<=0.04 range, and 89 galaxies with both a redshift within the cluster redshift range and a measured r' band magnitude (limited to the Megacam 1x1deg^2^ field).
- ID:
- ivo://CDS.VizieR/J/ApJ/809/59
- Title:
- Ophiuchus stellar stream with PS1 data
- Short Name:
- J/ApJ/809/59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Ophiuchus stream is a recently discovered stellar tidal stream in the Milky Way. We present high-quality spectroscopic data for 14 stream member stars obtained using the Keck and MMT telescopes. We confirm the stream as a fast moving (v_los_~290km/s), kinematically cold group ({sigma}_{nu}_los__<~1km/s) of {alpha}-enhanced and metal-poor stars ([{alpha}/Fe]~0.4dex, [Fe/H]~-2.0dex). Using a probabilistic technique, we model the stream simultaneously in line-of-sight velocity, color-magnitude, coordinate, and proper motion space, and so determine its distribution in 6D phase-space. We find that the stream extends in distance from 7.5 to 9kpc from the Sun; it is 50 times longer than wide, merely appearing highly foreshortened in projection. The analysis of the stellar population contained in the stream suggests that it is ~12Gyr old, and that its initial stellar mass was ~2x10^4^M_{sun}_ (or at least >~7x10^3^M_{sun}_). Assuming a fiducial Milky Way potential, we fit an orbit to the stream that matches the observed phase-space distribution, except for some tension in the proper motions: the stream has an orbital period of ~350Myr, and is on a fairly eccentric orbit (e~0.66) with a pericenter of ~3.5kpc and an apocenter of ~17kpc. The phase-space structure and stellar population of the stream show that its progenitor must have been a globular cluster that was disrupted only ~240Myr ago. We do not detect any significant overdensity of stars along the stream that would indicate the presence of a progenitor, and conclude that the stream is all that is left of the progenitor.
