Definitive Nuclear Stellar Disk membership of the central Cepheids

Determine whether the three classical Cepheids GCC-a, GCC-b, and GCC-c genuinely belong to the Milky Way Nuclear Stellar Disk rather than being interlopers passing through or projected against the nuclear region.

Background

The three Cepheids have six-dimensional phase-space information and were analyzed using orbit integrations in a time-varying Milky Way potential. The analysis favors GCC-a as a likely NSD member, whereas GCC-b and GCC-c generally have orbits extending beyond the NSD; however, observational uncertainties, especially in the distance estimates, leave a non-negligible fraction of orbital realizations compatible with NSD membership.

Because the membership of these young variables determines whether they provide evidence for a recent star-formation burst in the NSD, a definitive classification is astrophysically important. The authors explicitly state that the available measurements and adopted potential models do not yield a conclusive membership assignment for all three Cepheids.