- ID:
- ivo://CDS.VizieR/VII/101A
- Title:
- Star Clusters/Associations. III. Open Clusters
- Short Name:
- VII/101A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue includes the Open Clusters of the supplement up to 1973 of the "Catalogue of Star Clusters and Associations" by Alter G., Ruprecht J., Vanysek V., Budapest 1970. The file "main.dat" contains the original data. For each cluster, the first line contains the running number (OCL) followed by various designations. The first five figures represent the galactic longitude (in 0.01degree), 'N' or 'S' for North or South galactic hemisphere, and galactic latitude (in 0.01degree). The second line contains the 1950 coordinates, the 50-yr precession, the galactic direction cosines and the position on the POSS charts. For each cluster a number of bibliographic records follow containing: YEAR: Year of the literature reference NAME: Author PUBLICATION: Reference AD: Angular diameter of the cluster in arc minutes DIST: Distance of the cluster (pc) LD: Linear diameter of the cluster (pc) N: Number of stars studied CI: Color index SP: Spectra P: Positions RV: Radial velocity (km/s) MT: Integrated magnitude NOTE: Notes The file "clusters" has been created from first and second lines; missing equatorial coordinates were derived from the galactic ones.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/436/1465
- Title:
- Star clusters distances and extinctions
- Short Name:
- J/MNRAS/436/1465
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Determining star cluster distances is essential to analyse their properties and distribution in the Galaxy. In particular, it is desirable to have a reliable, purely photometric distance estimation method for large samples of newly discovered cluster candidates e.g. from the Two Micron All Sky Survey, the UK Infrared Deep Sky Survey Galactic Plane Survey and VVV. Here, we establish an automatic method to estimate distances and reddening from near-infrared photometry alone, without the use of isochrone fitting. We employ a decontamination procedure of JHK photometry to determine the density of stars foreground to clusters and a galactic model to estimate distances. We then calibrate the method using clusters with known properties. This allows us to establish distance estimates with better than 40 percent accuracy. We apply our method to determine the extinction and distance values to 378 known open clusters and 397 cluster candidates from the list of Froebrich, Scholz & Raftery (2007MNRAS.374..399F, Cat. J/MNRAS/374/399). We find that the sample is biased towards clusters of a distance of approximately 3kpc, with typical distances between 2 and 6kpc. Using the cluster distances and extinction values, we investigate how the average extinction per kiloparsec distance changes as a function of the Galactic longitude. We find a systematic dependence that can be approximated by A_H_(l)[mag/kpc]=0.10+0.001x|l-180{deg}|/{deg} for regions more than 60{deg} from the Galactic Centre.
- ID:
- ivo://CDS.VizieR/J/MNRAS/444/290
- Title:
- Star clusters distances and extinctions. II.
- Short Name:
- J/MNRAS/444/290
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Until now, it has been impossible to observationally measure how star cluster scaleheight evolves beyond 1Gyr as only small samples have been available. Here, we establish a novel method to determine the scaleheight of a cluster sample using modelled distributions and Kolmogorov-Smirnov tests. This allows us to determine the scaleheight with a 25% accuracy for samples of 38 clusters or more. We apply our method to investigate the temporal evolution of cluster scaleheight, using homogeneously selected sub-samples of Kharchenko et al. (MWSC, 2012, Cat. J/A+A/543/A156, 2013, J/A+A/558/A53 ), Dias et al. (DAML02, 2002A&A...389..871D, Cat. B/ocl), WEBDA, and Froebrich et al. (FSR, 2007MNRAS.374..399F, Cat. J/MNRAS/374/399). We identify a linear relationship between scaleheight and log(age/yr) of clusters, considerably different from field stars. The scaleheight increases from about 40pc at 1Myr to 75pc at 1Gyr, most likely due to internal evolution and external scattering events. After 1Gyr, there is a marked change of the behaviour, with the scaleheight linearly increasing with log(age/yr) to about 550pc at 3.5Gyr. The most likely interpretation is that the surviving clusters are only observable because they have been scattered away from the mid-plane in their past. A detailed understanding of this observational evidence can only be achieved with numerical simulations of the evolution of cluster samples in the Galactic disc. Furthermore, we find a weak trend of an age-independent increase in scaleheight with Galactocentric distance. There are no significant temporal or spatial variations of the cluster distribution zero-point. We determine the Sun's vertical displacement from the Galactic plane as Z_{sun}_=18.5+/-1.2pc.
1044. Star Clusters in M33
- ID:
- ivo://CDS.VizieR/J/ApJS/122/431
- Title:
- Star Clusters in M33
- Short Name:
- J/ApJS/122/431
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the discovery of 60 star clusters in 20 multiband Hubble Space Telescope (HST) WFPC2 fields in M33. The fields sample a variety of environments, from outer regions to spiral arms and central regions, as well as a range of galactocentric distances. The HST spatial resolution allowed us to penetrate the crowded, spiral arm regions of M33 yielding the first unbiased, representative sample of star clusters for this galaxy. We discuss the separation of clusters from stellar sources, and from other extended sources such as star-forming regions, H II regions, and supernova remnants. For the clusters we present multiband images and discuss morphology, location, and integrated photometry. Measured cluster colors and magnitudes are presented. The cluster density in our sample as a function of galactocentric distance yields an estimate of 690 total clusters in M33.
1045. Star clusters in M33
- ID:
- ivo://CDS.VizieR/J/MNRAS/451/3400
- Title:
- Star clusters in M33
- Short Name:
- J/MNRAS/451/3400
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present precision radial velocities and stellar population parameters for 77 star clusters in the Local Group galaxy M33. Our Gran Telescopio de Canarias and William Herschel Telescope observations sample both young, massive clusters and known/candidate globular clusters (GCs), spanning ages ~10^6-10^10yr, and metallicities, [M/H]~-1.7 to solar. The cluster system exhibits an age-metallicity relation; the youngest clusters are the most metal rich. When compared to HI data, clusters with [M/H]~-1.0 and younger than ~4Gyr are clearly identified as a disc population. The clusters show evidence for strong time evolution in the disc radial metallicity gradient (d[M/H]dt/dR=0.03dex/kpc/Gyr). The oldest clusters have stronger, more negative gradients than the youngest clusters in M33. The clusters also show a clear age-velocity dispersion relation. The line-of-sight velocity dispersions of the clusters increases with age similar to Milky Way open clusters and stars. The general shape of the relation is reproduced by disc heating simulations, and the similarity between the relations in M33 and the Milky Way suggests that heating by substructure and cooling of the interstellar medium both play a role in shaping this relation. We identify 12 'classical' GCs, six of which are newly identified GC candidates. The GCs are more metal rich than Milky Way halo clusters, and show weak rotation. The inner (R<4.5kpc) GCs exhibit a steep radial metallicity gradient (d[M/H]/dR=-0.29+/-0.11dex/kpc) and an exponential-like surface density profile. We argue that these inner GCs are thick disc rather than halo objects.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A89
- Title:
- Star clusters in the Magellanic Clouds
- Short Name:
- J/A+A/602/A89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To produce an homogeneous catalog of astrophysical parameters of 239 resolved star clusters located in the Small and Large Magellanic Clouds, observed in the Washington photometric system. The cluster sample was processed with the recently introduced Automated Stellar Cluster Analysis (ASteCA) package, which ensures both an automatized and a fully reproducible treatment, together with a statistically based analysis of their fundamental parameters and associated uncertainties. The fundamental parameters determined with this tool for each cluster, via a color-magnitude diagram (CMD) analysis, are: metallicity, age, reddening, distance modulus, and total mass. We generated an homogeneous catalog of structural and fundamental parameters for the studied cluster sample, and performed a detailed internal error analysis along with a thorough comparison with values taken from twenty-six published articles. We studied the distribution of cluster fundamental parameters in both Clouds, and obtained their age-metallicity relationships. The ASteCA package can be applied to an unsupervised determination of fundamental cluster parameters; a task of increasing relevance as more data becomes available through upcoming surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/430/941
- Title:
- Star formation region NGC 6530
- Short Name:
- J/A+A/430/941
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present astrometry and BVI photometry, down to V~22, of the very young open cluster NGC 6530, obtained from observations taken with the Wide Field Imager camera at the MPG/ESO 2.2m Telescope. We have positionally matched our optical catalog with the list of X-ray sources found in a Chandra-ACIS observation, finding a total of 828 common stars, 90% of which are pre-main sequence stars in NGC 6530.
- ID:
- ivo://CDS.VizieR/J/MNRAS/496/3358
- Title:
- Star Forming Region IRAS12272-6240 JHK photometry
- Short Name:
- J/MNRAS/496/3358
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IRAS 12272-6240 is a complex star-forming region with a compact massive dense clump (DC) and several associated masers, located at a well-determined distance of d=9.3kpc from the Sun. For this study, we obtained sub-arcsec broad- and narrow-band near-infrared (near-IR) imaging and low-resolution spectroscopy with the Baade/Magellan telescope and its camera PANIC. Mosaics of size 2x2arcmin^2^ in the JHKs bands and with narrow-band filters centred in the 2.12um H_2_ and 2.17um Br{gamma} lines were analysed in combination with Hi-GAL/Herschel and archive IRAC/Spitzer and WISE observations. We found that the compact DC houses two Class I young stellar objects (YSOs) that probably form a 21000-au-wide binary system. Its combined 1-1200um spectral energy distribution is consistent with an O9V central star with a 10^-2^M_{sun}_ disc and a 1.3x10^4^M_{sun}_ dust envelope. Its total luminosity is 8.5x10^4^L_{sun}_. A series of shocked H_2_ emission knots are found in its close vicinity, confirming the presence of outflows. IRAS 12272-6240 is at the centre of an embedded cluster with a mean age of 1Myr and 2.6pc in size that contains more than 150 stars. At its nucleus, we found a more compact and considerably younger subcluster containing the YSOs. We also identified and classified the O-type central stars of two dusty radio/IR HII regions flanking the protostars. Our results confirm that these elements form a single giant young complex where massive star formation processes started some 1Myr ago and are still active.
- ID:
- ivo://CDS.VizieR/J/AN/283/109
- Title:
- Star positions in the region of alpha Per
- Short Name:
- J/AN/283/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This file contains 1221 stars observed for spectral type in the field of the alpha Persei cluster. The types were published in the well known proper-motion survey by Heckmann et al. (1956AN....283..109H), and were determined by Wachmann with the equipment and methods used for the Bergedorf selected areas surveys (BSD). In general the brighter HD stars were not observed for spectral type, but most of these have been classified on the MK system by Roman & Morgan (1950ApJ...111..426R) and in later work. Nearly all the stars are included in SIMBAD with the source positions, and most also appear in WEBDA with these data as well. The positions below are nearly all from UCAC2 (for both epoch and equinox J2000), and thus differ by a few arcsec mainly from proper motion, but also from the systematic shift between the FK3 to the ICRS. In general the spectral types are not present in SIMBAD or WEBDA. I worked from Alain Fresneau's compilation for the field, which is based largely on the Heckmann data (Cat. <I/68>). I ran those coordinates into VizieR looking at UCAC2, Tycho-2, and the Fabricius Tycho double-star catalogue (Cat. <I/276>). Coordinates for two crowded stars were obtained from 2MASS. With one exception all the stars were found quite close to the predicted positions. Close pairs are indicated in the notes, as are stars with substantial proper motion (>>0.1"/year).
- ID:
- ivo://CDS.VizieR/J/A+A/521/A61
- Title:
- Stars associated to Eagle Nebula (M16=NGC6611)
- Short Name:
- J/A+A/521/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Massive star-forming regions are characterized by intense ionizing fluxes, strong stellar winds and, occasionally, supernovae explosions, all of which have important effects on the surrounding media, on the star-formation process and on the evolution of young stars and their circumstellar disks. We present a multiband study of the massive young cluster NGC 6611 and its parental cloud (the Eagle Nebula) with the aim of studying how OB stars affect the early stellar evolution and the formation of other stars. We search for evidence of triggering of star formation by the massive stars inside NGC 6611 on a large spatial scale (~10 parsec) and ongoing disk photoevaporation in NGC 6611 and how its efficiency depends on the mass of the central stars.
