CCD UBV(RI)KC photometry of the open cluster NGC 6793 and its dynamical evolution
Journal of Astrophysics and Astronomy, cilt.47, sa.2, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 47 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s12036-026-10168-x
- Dergi Adı: Journal of Astrophysics and Astronomy
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, INSPEC, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Earth, Atmospheric, & Aquatic Science Collection (ProQuest), Engineering Source (EBSCO), Technology Collection (ProQuest)
- Anahtar Kelimeler: (Galaxy), abundances-Galaxy, evolution, general-Galaxy, open clusters and associations
- Erciyes Üniversitesi Adresli: Evet
Özet
We present new astrophysical parameters for the open cluster NGC 6793 based on new CCD UBV(RI)KC photometry. We derived a reddening of E(B-V)=0.24±0.02 mag and a heavy element abundance of Z=0.024 ([Fe/H]=+0.20 dex). Padova isochrone fitting to the V×(B-V) colour-magnitude diagram yields an intermediate age of 525±51 Myr and a distance modulus of μ=8.80±0.05 mag, corresponding to a distance of d=575±58 pc from the Sun. The core radius of NGC 6793 appears to be shrinking due to advanced dynamical evolution (logτ2=1.13), driven by mass segregation and the evaporation of low-mass stars from the central region. The ratios of core to half-mass radius (Rc/Rh) and half-mass to Jacobi radius (Rh/RJ) indicate that the cluster’s evolution is governed by the combined effects of internal two-body relaxation, mass segregation, and external tidal perturbations. The ratio Rt/RJ=0.99 suggests that the cluster is currently in a tidally filling state. The parameter pairs (tdiss/trlx1=40, logRJ/Rc=0.72) and (Rh/RJ=0.38, logρamb=-0.88) place NGC 6793 among the relatively compact clusters within RGC<7.9 kpc. This implies a compact internal structure that is stable against the combined effects of two-body encounters and tidal heating. Given its current state, NGC 6793 will likely dissolve and disperse before entering the final contraction phase (R4 regime).