| dc.description.abstract | oindent Berkeley 17, located at a heliocentric distance of 2700 pc, is among the oldest Galactic open
clusters. The cluster is noted to resemble globular clusters for its ~10 Gyr age, [Fe/H] of -0.33
subsolar metallicity, excessive number of blue stragglers, and a prominent horizontal branch. The
cluster displays an elongated shape due to a tail and anti-tail. In previous analysis of its core-tail
morphology, massive stars outnumber less massive ones. This indicated the effect of dynamical
mass segregation, where massive members ′sink′ to the core, while the low-mass members occupy
larger volumes. The cause of this phenomenon is unclear, however, one possible tidal source is the
Perseus arm, where distinct field population of Berkeley 17 is attributed to. Multi-wavelength
photometry and astrometry from PS1, 2MASS, AllWISE, and GAIA EDR3 were processed to gain
the disintegrating cluster’s highest-probable members and their spectral types, as well as current
stage in dynamical evolution.
Almost half of the previously known members are removed due to parallax and proper motion, also reducing the blue straggler population from 21 to 12. LAMOST spectrosocpy returned a near solar metallicity at [Fe/H] = -0.175 dex. Galactic motion also suggests that Berkeley 17 is heavily affected by the Perseus arm due to its motion against the Galactic rotation and towards the Galactic center. | en_US |