DEEP UBVRI PHOTOMETRY IN THE CORE OF NGC 5606

R.A. VÁZQUEZ; G. BAUME; A. FEINSTEIN; P. PRADO

ASTRONOMY & ASTROPHYSICS. SUPPLEMENT SERIES (PRINT)

ASTRONOMY & ASTROPHYSICS

Año: 1994 p. 339 - 348

0365-0138

The center of the open cluster NGC 5606 has been re-observed with broad band UBVRI CCD photometry. Up to V = 18.5 likely cluster members are found underlining a sharp but not so populated cluster sequence. With this new photometry the cluster distance modulus is stated in V_0_-M_v_=11.90 (d=2400pc). The mean colour excess reaches the value =0.51. The age of the cluster from the isochrone fitting is between 6.3x10^6^ and 7x10^6^ y. Surprisingly enough there are not many stars found below V=15.5 in spite of the fact that we are observing the very core of the cluster. This lack of faint cluster stars produces in turn a flat slope for the cluster mass spectrum. In this respect our computation yields x=1.09 far enough of x=1.35 which is assumed to be the slope characterizing the mass spectrum of galactic stars.