A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F21%3A00122382" target="_blank" >RIV/00216224:14310/21:00122382 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1007/s10509-021-03975-x" target="_blank" >https://doi.org/10.1007/s10509-021-03975-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s10509-021-03975-x" target="_blank" >10.1007/s10509-021-03975-x</a>

Result language

angličtina

Original language name

A study of the Czernik 2 and NGC 7654 open clusters using CCD UBV photometric and Gaia EDR3 data

Original language description

We analysed the open clusters Czernik 2 and NGC 7654 using CCD UBV photometric and Gaia Early Data Release 3 (EDR3) photometric and astrometric data. Structural parameters of the two clusters were derived, including the physical sizes of Czernik 2 being r=5′ and NGC 7654 as 8′. We calculated membership probabilities of stars based on their proper motion components as released in the Gaia EDR3. To identify member stars of the clusters, we used these membership probabilities taking into account location and the impact of binarity on main-sequence stars. We used membership probabilities higher than P=0.5 to identify 28 member stars for Czernik 2 and 369 for NGC 7654. The mean proper motion components (μαcosδ, μδ) of Czernik 2 were derived as (−4.03±0.04, −0.99±0.05) mas yr−1 and for NGC 7654 as (−1.89±0.03, −1.20±0.03) mas yr−1. We estimated colour-excesses and metallicities separately using (U−B)×(B−V) two-colour diagrams to derive homogeneously determined parameters. The derived E(B−V) colour excess is 0.46±0.02 mag for Czernik 2 and 0.57±0.04 mag for NGC 7654. [Fe/H] metallicities were obtained for the first time for both clusters, −0.08±0.02 dex for Czernik 2 and −0.05±0.01 dex for NGC 7654. Keeping the reddening and metallicity as constant quantities, we fitted PARSEC models using V×(B−V) and V×(U−B) colour-magnitude diagrams, resulting in estimated distance moduli and ages of the two clusters. We obtained the distance modulus for Czernik 2 as 12.80±0.07 mag and for NGC 7654 as 13.20±0.16 mag, which coincide with ages of 1.2±0.2 Gyr and 120±20 Myr, respectively. The distances to the clusters were calculated using the Gaia EDR3 trigonometric parallaxes and compared with the literature. We found good agreement between the distances obtained in this study and the literature. Present day mass function slopes for both clusters are comparable with the value of Salpeter (1955), being X=−1.37±0.24 for Czernik 2 and X=−1.39±0.19 for NGC 7654.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astrophysics and Space Science

ISSN

0004-640X

e-ISSN

1572-946X

Volume of the periodical

366

Issue of the periodical within the volume

7

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

19

Pages from-to

68

UT code for WoS article

000692376300001

EID of the result in the Scopus database

2-s2.0-85111306945