Access to Astronomical Catalogues

← Click to display the menu
J/AJ/134/1216  Abundances of NGC 7142, 6939, and IC 4756 stars (Jacobson+, 2007)

Na, al, and O abundances of open clusters NGC 7142, NGC 6939, and IC 4756. Jacobson H.R., Friel E.D., Pilachowski C.A. <Astron. J., 134, 1216-1230 (2007)> =2007AJ....134.1216J
ADC_Keywords: Clusters, open ; Abundances Keywords: Galaxy: abundances - open clusters and associations: individual (NGC 7142, NGC 6939, IC 4756) - stars: abundances Abstract: We present an analysis of echelle spectra of stars in three open clusters obtained with the Hydra multiobject spectrograph on the WIYN 3.5m telescope. Abundances of Fe, O, Si, Ca, Na, Al, and Ni have been determined via equivalent width analysis and spectrum synthesis. Mean abundances for each cluster are compared to those of previous studies and of other clusters in the literature, with emphasis on exploring the enhancements of Na and Al seen in many open clusters. All three clusters show enhanced values of [Na/Fe] and [Al/Fe], while the abundances of Fe, O, Si, and Ca are consistent with their ages and locations in the Galactic disk. Description: Single-order echelle spectra of stars in each cluster were obtained with the Hydra multiobject spectrograph on the WIYN 3.5m telescope in the fall of 2005. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 21 45 09 +65 46.5 NGC 7142 = Cl Collinder 442 20 31 30 +60 39.7 NGC 6939 = Cl Melotte 231 18 38 31.2 +05 29 24 IC 4756 = Cl Melotte 210 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file stars.dat 72 44 NGC 7142, NGC 6939 and IC 4756 stars observed table4.dat 46 927 Equivalent widths
Byte-by-byte Description of file: stars.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Cluster Cluster name 10- 13 I4 --- Star Star number within the cluster (1) 15- 18 I4 --- WEBDA ? WEBDA star number 20- 24 F5.2 mag Vmag V magnitude 26- 29 F4.2 mag B-V B-V colour index 31- 34 F4.2 mag V-K V-K colour index 36- 39 F4.2 mag J-K J-K colour index (2MASS) 41- 43 I3 --- S/N Signal-to-noise ratio (Average of Na and Al data) 45- 49 F5.1 km/s RV Radial velocity 51- 56 F6.2 km/s RV2 ? Radial velocity from Mermilliod & Mayor, 1990A&A...237...61M 58- 69 A12 --- Memb Membership, with comments 72 A1 --- EW [*] indicates equivalent width data in table4
Note (1): Identification lists are: * For NGC 7142, Identification from Crinklaw & Talbert, (1991PASP..103..536C), Cl* NGC 7142 CT NNN in Simbad * For NGC 6939, Identification from Kustner (1923VeBon..18....1K), NGC 6939 NNN in Simbad * For IC 4756, Identification from Kopff (1943AN....274...69K) IC 4756 NNNN in Simbad
Byte-by-byte Description of file: table4.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Cluster Cluster name 10- 12 I3 --- Star Star number within the cluster 14- 18 A5 --- Ion Ion identification 20- 27 F8.3 0.1nm lambda Wavelength in Angstroms 29- 33 F5.3 eV ExPot Excitation potential 35- 40 F6.3 [-] log(gf) Log of the oscillator strength 42- 46 F5.1 10-13m EW ? Equivalent width
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 04-Oct-2009
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact