CCD UBV(RI)KC and GAIA photometry of NGC 2323, NGC 2539, Juchert 9 and Berkeley 97 open clusters
Abstract
The open clusters NGC 2323, NGC 2539, Juchert 9 (Juc 9) and Berkeley 97 (Be 97) have been analysed using CCD UBV(RI)KC photometric data, observed at the San Pedro Mártir Observatory. Cluster memberships 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 δ(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, Juc09 and Be 97, we determined the reddenings as E(B − V) = 0.02 ± 0.06, E(B-V)=0.82±0.04 and E(B-V)=0.87±0.05 with respectively. Also we find distance moduli and distances for these four star clusters are derived as (V0 − MV , d (pc)) = (10.00 ± 0.10, 1000 ± 50) and (V0 − MV , d(pc)) = (10.00 ± 0.04, 1000 ± 20), (V0 − MV , d (pc)) = (13.40±0.10, 4.8±0.2), (V0 − MV , d (pc)) = (12.40±0.12, 3.0±0.2). The median GaiaDR2 distance d = 1000 ± 140 pc ( = 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 ( = 0.751±0.139 mas) is close to its four-colour photometric distances, 1000 pc. The Gaia DR2 distances are d=4.5±1.2 kpc (Juc 9) and d=3.1±0.7 kpc (Be 97) from the median parallaxes . which are in good agreement with the photometric distances within the uncertainties. 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. The solar abundance PARSEC isochrones give us the intermediate ages, 30±10 Myr for Juc 9 and 100±30 Myr for Be 97.
- Publication:
-
43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1539O