CCD UBVRI photometry of the open cluster Berkeley 8

Abstract

The poorly studied Berkeley 8 (Be 8) open cluster is analyzed from CCD UBVRI photometric data taken with the 0.90 m telescope at the Sierra Nevada Observatory. The Z = +0.008 PARSEC isochrone gave us a reddening of E(B-V) = 0.69 +/- 0.03, a distance of 3410 +/- 300 pc, and an age of 2.8 +/- 0.2 Gyr. Its median Gaia DR2 distance, d = 3676 +/- 810 pc, is in good agreement with our photometric distances, 3410-3620 pc within the uncertainties. The kinematic parameters of five likely members of Be 8 with the circular orbits, ecc = [0.23, 0.30] , reflect the properties of the Galactic thin disc, which is also consistent with what is expected of its metal content ([M/H] = -0.27). Be 8 with R > 9 kpc (co-rotation gap at 9 kpc) may have been originating from a different galactic radius or different star formation region.