THE ASTROMETRIC ACCURACY OF CARTE-DU-CIEL PLATES AND PROPER MOTIONS IN THE FIELD OF THE OPEN CLUSTER NGC-1647

Authors
GEFFERT M BONNEFOND P MAINTZ G GUIBERT J
Citation
M. Geffert et al., THE ASTROMETRIC ACCURACY OF CARTE-DU-CIEL PLATES AND PROPER MOTIONS IN THE FIELD OF THE OPEN CLUSTER NGC-1647, Astronomy & Astrophysics. Supplement series, 118(2), 1996, pp. 277-282
Citations number
13
Categorie Soggetti
Astronomy & Astrophysics
Journal title
Astronomy & Astrophysics. Supplement series → ACNP
ISSN journal
03650138
Volume
118
Issue
2
Year of publication
1996
Pages
277 - 282
Database
ISI
SICI code
0365-0138(1996)118:2<277:TAAOCP>2.0.ZU;2-R
Abstract
The astrometric accuracy of triple image Carte du Ciel plates has been analysed using plates of the open cluster NGC 1647. A new multithresh old technique was used for the treatment of the triple image plates. A ccuracies ranging from 100 mas to 200 mas were found. We determined pr oper motions with a median accuracy of 1.6 mas/a for 2220 stars in the field of NGC 1647. The membership probabilities of stars in the clust er region agree very well with the data of Francic (1989). Due to a si gnificant difference of the proper motions of SZ Tau and the cluster m embers, SZ Tau seems not to be a member of NGC 1647.