CCD UBVI photometry and polarimetry in the open cluster trumpler 21

Authors
Giorgi, EE Baume, G Vazquez, RA Feinstein, A
Citation
Ee. Giorgi et al., CCD UBVI photometry and polarimetry in the open cluster trumpler 21, REV MEX AST, 37(1), 2001, pp. 15-33
Citations number
25
Categorie Soggetti
Space Sciences
Journal title
REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA
ISSN journal
01851101 → ACNP
Volume
37
Issue
1
Year of publication
2001
Pages
15 - 33
Database
ISI
SICI code
0185-1101(200104)37:1<15:CUPAPI>2.0.ZU;2-3
Abstract
CCD UBVI photometry was carried out in the field of the open cluster Trumpl er 21. Our data locate the cluster at a distance of 1380 pc in a low absorp tion zone with E(B - V) = 0.25. The age of the cluster is estimated to be 2 5 - 30 x 10(6) yr based on the superposition of isochrones computed with ma ss loss and overshooting. The cluster mass spectrum has a slope of 1.44 sim ilar to the typical value 1.35 for field stars. UBVRI polarimetry of its br ightest members led us to the finding that diffuse interstellar material is responsible for both polarization percentage and its direction.