A Gaia based analysis of open cluster Berkeley 27

Abstract

In this paper, we have used the Gaia’s Data Release-3 (DR3) data to study an intermediate-age open cluster Berkeley 27 (Be 27). A total of 131 most probable cluster members are picked within the cluster’s radius based on the membership probability (>80%). The cluster’s radius was estimated as 3.74 arcmin. The mean proper motion (PM) of Be 27 was determined to be (𝜇𝛼 𝑐𝑜𝑠𝛿, 𝜇𝛿 )= (−1.076 ± 0.008, 0.152 ± 0.007) mas yr−1 . The blue straggler stars (BSS) of the cluster were found to be located in the central region. Theoretical isochrones of metallicity Z𝑚𝑒𝑡𝑎𝑙 = 0.008 were compared to the color-magnitude diagram (CMD) of Be 27. As a result, a heliocentric distance of 4.8 ± 0.2 kpc and log (age) = 9.36 ± 0.03 were determined for Be 27. The Galactic orbits are derived using the Galactic potential model which demonstrate that Be 27 follows a circular path around the Galactic center. The cluster does not seem to be affected much by the tidal forces from the Galactic thin disk.