2025/12/04 by Ashraf, Mizna, Jose, Jessy, Herczeg, Gregory J. +6
#FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2512.04645
The metallicity of the star-forming environment is a fundamental parameter shaping the evolution of protoplanetary disks and the formation of planetary systems, yet its influence remains poorly constrained. We present a spectroscopic study of low-mass pre-main sequence (PMS) stars (M < 1 M_\odot) in the exceptionally metal-poor cluster Dolidze~25 (Z ≈ 0.2 Z_\odot), using VLT/MUSE observations to probe accretion processes and disk evolution in a subsolar environment. We identify 132 cluster members using a combination of Gaia astrometry and spectroscopic youth indicators, including lithium absorption and Balmer emission. The stellar parameters are derived using low-metallicity BT-Settl models yielding effective temperatures, extinctions, luminosities enabling robust estimates of stellar masses and ages. Mass accretion rates (Macc) derived from Hα emission span 10-10--10-8 M_\odot yr-1 with a median value of \(8 × 10-10 M_\odot yr-1\). These rates are comparable to those in solar-metallicity regions of similar age, such as Lupus and Orion, indicating minimal metallicity dependence in accretion processes. Our analysis shows that using solar-metallicity templates to fit low-metallicity stars leads to systematic overestimations of \(Teff\) (by approximately \(300 K\)) and \(AV\) (by around \(0.5 mag\)), underscoring the importance of employing metallicity-matched models for reliable characterization in low-\(Z\) environments. We present flux-calibrated, extinction-corrected spectra of these metal-poor PMS stars as a valuable resource for future investigations of disk evolution in subsolar regimes.