UI CCD photometry of Berkeley 55 open cluster


AKKAYA ORALHAN İ.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY, vol.42, no.2, 2021 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 2
  • Publication Date: 2021
  • Doi Number: 10.1007/s12036-021-09757-9
  • Title of Journal : JOURNAL OF ASTROPHYSICS AND ASTRONOMY

Abstract

Fundamental astrophysical parameters have been derived for Berkeley 55 (Be 55) open cluster based on the UBVI charge-coupled device (CCD) photometric data observed using a AZT-22 1.5 m telescope at Maidanak Astronomical Observatory (MAO) in Uzbekistan. The mean reddening is obtained as E(B-V)=1.77 +/- 0.10mag from early-type members. The zero-age main sequence fitting in the QV lambda - Q ' diagrams indicates the distance modulus, (V0-MV)=12.4 +/- 0.20. This photometric distance is consistent with the distances of Gaia EDR3 (d=3.09 +/- 0.16 and period-luminosity relation (d= 2.78 +/- 0.32 kpc) of its Cepheid S5 within the uncertainties. This distance also locates the cluster near the Perseus spiral arm. The Geneva isochrone fittings to the Hertzsprung-Russell diagram and observational colour-magnitude diagrams derive turn-off age, 85 +/- 13 Myr, by taking care of five red supergiants/bright giants. The possible inconsistencies in the locations of the bright giants with the rotating/non-rotating isochrones may be due to both the age spread of stars in young open clusters and the diversity in rotational velocities.