Mikhaela Gallardo (Graduate Institute of Astronomy, National Central University, Taiwan); Chow-Choong Ngeow (Graduate Institute of Astronomy, National Central University, Taiwan); W.P. Chen (Graduate Institute of Astronomy, National Central University, Taiwan)
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.