OPTICAL PHOTOMETRY AND CORAVEL OBSERVATIONS OF STARS IN THE FIELD OF THE HYADES-LIKE AGE OPEN CLUSTER NGC2489

A.E. PIATTI; J.J. CLARIÁ; J.-C. MERMILLIOD; M.C.PARISI; A.V. AHUMADA

Isla Margarita - Venezuela

Congreso; XII IAU Regional Latin American Meeting of Astronomy; 2007

We present CCD BVI photometry of 2182 stars in the field of the open cluster NGC2489, supplemented with Coravel radial-velocity observations for 7 red giant candidates. The comparison of the cluster colour-magnitude diagram with isochrones of the Padova group yields E(B-V) = 0.30 ± 0.05, E(V-I) = 0.40 ± 0.05, and V-MV = 12.20 ± 0.25 for log t = 8.70 and Z = 0.019. NGC2489 is then located at 1.8 ± 0.3 kpc from the Sun and 25 pc below the Galactic plane. A cluster angular radius of 6.7
± 0.6
, equivalent to (3.5 ± 0.3) pc, is estimated from star counts carried out inside and outside the cluster region. The analysis of the kinematical data allowed us to confirm cluster membership for 6 red giants, one of them being a spectroscopic binary. A mean radial velocity of 38.13 ± 0.33 km/s was derived for these stars. The properties of a sample of open clusters aligned along the line-of-sight to NGC2489 are examined (Piatti, A.E., et al., 2007, MNRAS, 377,  1737).