OPENCLUST - New Optically Visible Open Clusters and Candidates Catalog

Overview

This is a new catalog of open clusters in the Galaxy which updates the previous catalogs of Lynga (1987, CDS Cat. VII/92, the HEASARC Browse table now called LYNGACLUST) and of Mermilliod (1995, in Information and On-Line Data in Astronomy, ed. D. Egret & M. A. Albrecht (Dordrecht: Kluwer), 127) (included in the WEBDA database, http://www.univie.ac.at/webda/). New objects and new data, in particular, data on kinematics (proper motions) that were not present in the old catalogs, have been included. Virtually all of the clusters presently known are included, which represents a large increase in the number of objects (almost 1,000) relative to the Lynga Catalog.

In total, 99.7% of the objects have estimates of their apparent diameters, and 74.5% have distance, E(B-V) and age determinations. Concerning the data on kinematics, 54.7% have their mean proper motions listed, 25% their mean radial velocities, and 24.2% have both information simultaneously.

Acknowledgments: Extensive use has been made by the authors of the SIMBAD and WEBDA databases. This project is supported by FAPESP (grant number 03/12813-4) and CAPES (CAPES-GRICES grant number 040/2008).

Catalog Bibcode

2002A&A...389..871D

Bulletin

The OPENCLUST database table was last updated on 17 September 2017.

References

New catalog of optically visible open clusters and candidates
    Dias W.S., Alessi B.S., Moitinho A., Lepine J.R.D.
   <Astron. Astrophys. 389, 871 (2002)>
   =2002A&A...389..871D

Provenance

This database table was originally created by the HEASARC in September 2002 based on the CDS version of the catalog. In March 2006, the HEASARC updated the table to use instead the following file obtained from the authors' web site: http://www.astro.iag.usp.br/ocdb/file/clusters.txt. In August 2017, the HEASARC reverted to using the CDS version of this catalog, available as the file clusters.dat at http://cdsarc.u-strasbg.fr/ftp/cats/B/ocl/.

HEASARC Implementation

There was a duplicate entry for the open cluster FSR 1496 in the input file obtained from the CDS, which the HEASARC have removed from its version of this table.

Parameters

Name
The name of the open cluster.

RA
The Right Ascension of the open cluster in the selected equinox. This was given in equinox J2000 and with a precision of 1 second of time in the original table.

Dec
The Declination of the open cluster in the selected equinox. This was given in equinox J2000 and with a precision of 1 arcsecond in the original table.

LII
The Galactic Longitude of the open cluster.

BII
The Galactic Latitude of the open cluster.

Type_Flag
A flag giving information on the open cluster as follows:

      A: possible asterism/dust hole/star cloud (no cluster)
     CR: Cluster Remnant (Pavani and Bica 2007, A&A, 468, 139)
      D: dubious, objects considered doubtful by the DSS images inspection
      E: embedded open cluster (or cluster associated with nebulosity)
      G: possible globular cluster
      M: possible moving group
      N: "non-existent NGC" (RNGC, Sulentic 1979, CDS Cat. <VII/1>). Some of
         Bica's POCRs (Possible Open Cluster Remnant, 2001, A&A, 366, 827)
         are also "non-existent NGC" objects.
     NF: objects not found in the DSS images inspection (wrong coordinates?)
      O: possible OB association (or detached part of)
     OE: O + E
    OEV: O + E + V
      P: POCR (Possible Open Cluster Remnant); (Bica et al. 2001, A&A, 366, 827)
      R: recovered, i.e. "non-existent NGC" that are well visible
         in the DSS images inspection
      V: clusters with variable extinction (Ahumada et al. 2001, A&A, 377, 845)
     OC: likely cluster (Kronberger M, private communication)
    OC?: possible cluster (Kronberger M, private communication)
     IR: discovered in infra-red but are visible in the DSS images inspection

Apparent_Diameter
The angular apparent diameter of the cluster, in arcminutes.

Distance
The heliocentric distance of the cluster as obtained from the WEBDA database (http://obswww.unige.ch/webda), in parsecs.

E_BV
The color excess or reddening of the cluster, E(B-V), in magnitudes.

Log_Age
The logarithm of the age of the open cluster, in years.

PM_RA
The mean proper motion of the cluster in the RA direction, in milliarcseconds per year (mas/yr).

PM_RA_Error
The standard deviation of the mean proper motion of the cluster in the RA direction, in mas/yr.

PM_Dec
The mean proper motion of the cluster in the Declination direction, in milliarcseconds per year (mas/yr).

PM_Dec_Error
The standard deviation of the mean proper motion of the cluster in the Declination direction, in mas/yr.

Num_Cluster_Stars
The estimated number of cluster members.

Ref_PM
A coded reference for the source of the mean proper motion determination. The key to the references is available at http://cdsarc.u-strasbg.fr/ftp/cats/B/ocl/refs.dat.

Rad_Vel
The cluster heliocentric radial velocity, in km/s.

Rad_Vel_Error
The uncertainty in the cluster radial velocity, in km/s.

Num_Rad_Vel_Stars
The number of stars used in the determination of the cluster radial velocity.

Ref_Rad_Vel
A coded reference for the source of the cluster radial velocity determination. The key to the references is available at http://cdsarc.u-strasbg.fr/ftp/cats/B/ocl/refs.dat.

Metallicity
The cluster metallicity, [Fe/H], relative to the solar value.

Metallicity_Error
The uncertainty in the cluster metallicity.

Num_Metallicity_Stars
The number of stars used in the determination of the cluster metallicity.

Trumpler_Type
The Trumpler type determined in the DSS inspection (degree of concentration-range of brightness-richness-nebulosity). See https://en.wikipedia.org/wiki/Open_cluster for a brief discussion of this classification scheme.

Contact Person

Questions regarding the OPENCLUST database table can be addressed to the HEASARC Help Desk.

Page Author: Browse Software Development Team
Last Modified: Monday, 16-Sep-2024 17:32:34 EDT