CCD Washington photometry of the moderately metal-poor open cluster NGC 2236

CLARIA OLMEDO, JUAN JOSÉ; PIATTI, ANDRÉS E.; PARISI, M.C.; AHUMADA, A.V.

Bol. Asociación Argentina de Astronomía

Eds. G. Dubner, M. Rovira, A.E. Piatti

Año: 2008 vol. 50 p. 93 - 96

CCD CT1 Washington photometry in the field of the open cluster NGC 2236 is presented, together with photoelectric CMT1T2 photometry of 13 red giant candidates. Based on the best fits of isochrones computed for Z = 0.008 to the (T1,C-T1) diagram, we derive reddening, distance and age. A metal abundance [Fe/H] = -0.3 +/- 0.2 is estimated from five independent abundance indices. We also derive a cluster core radius of r_c = 1.2 pc and an annular cluster corona of Delta(r_c) =  2.2 pc. The properties of a sample of 20 known open clusters aligned along the line-of-sight to NGC 2236 are examined.