CCD UBV(RI)(KC) photometry of NGC 2323 and NGC 2539 open clusters

AKKAYA ORALHAN İ., Michel R., Schuster W. J., Karatas Y., Karsli Y., Chavarria C.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY, cilt.40, sa.4, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 40 Sayı: 4
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1007/s12036-019-9600-7
  • Dergi Adı: JOURNAL OF ASTROPHYSICS AND ASTRONOMY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: Galaxy evolution, open clusters and associations-individual, Hertzsprung-Russell and colour magnitude diagrams, THEORETICAL ISOCHRONES, PROPER MOTIONS, STARS, SEARCH, EVOLUTION, MODELS, TRACKS, DUST, AGE
  • İstanbul Üniversitesi Adresli: Evet

Özet

The open clusters NGC 2323 and NGC 2539 have been analysed using CCD UBV(RI)(KC) photometric data, observed at the San PedroMartir Observatory. Clustermemberships have been determined with the proper motion and parallax measures from the GaiaDR2 astrometric data release. Photometric metal and heavy element abundances have been obtained as ([M/H], Z) = (-0.10, 0.012) (NGC 2323) and (-0.31, 0.007) (NGC 2539) from the delta(U-B) technique in the two-colour diagrams, which are used to select the appropriate PARSEC isochrones. The estimated reddening of NGC 2323 is E(B - V) = 0.23 +/- 0.04 using 11 early type stars. For NGC 2539, we find E(B - V) = 0.02 +/- 0.06. For (B - V) colour, distance moduli and distances for NGC 2323 and NGC 2539 are derived as (V-0 -M-V, d (pc)) = (10.00 +/- 0.10, 1000 +/- 50) and (V-0 - M-V, d(pc)) = (10.00 +/- 0.04, 1000 +/- 20), respectively. The median GaiaDR2 distance d = 1000 +/- 140 pc (omega = 0.998 +/- 0.136 mas) for the likely members of NGC 2323 is in concordance with its four-colour photometric distances 910-1000 pc. For NGC 2539, its GaiaDR2 distance d = 1330 +/- 250 pc (omega = 0.751 +/- 0.139 mas) is close to its four-colour photometric distances, 1000 pc. Fitting the PARSEC isochrones to the colour magnitude diagrams (CMDs) gives an old age, 890 +/- 110 Myr, for NGC 2539. Whereas NGC 2323 has an intermediate age, 200 +/- 50 Myr. One red clump/red giant candidate (BD-12 2380) in the CMDs of NGC 2539 has been confirmed as a member in terms of the distances d(I) = 950 +/- 50 pc and d(V) = 910 +/- 90 pc of V I filters within the uncertainties, as compared to the distance 1000 +/- 20 pc of NGC 2539. This giant's GaiaDR2 distance (d = 1200 +/- 70 pc) is not close to these photometric distances.