2011/06/06 by M. Otulakowska, Otulakowska, M., A. Olech +10
Physics and Astronomy · #Astronomy and Astrophysical Research #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.1106.1123
18 pages, 9 figures, submitted to Acta Astronomica
arxiv created 2011/06/06 · openalex publication_date 2011/06/06 · arxiv updated 2011/06/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present results of new photometry for the globular star cluster NGC 2155 in the Large Magellanic Cloud (LMC). Our I- and V-band observations were obtained with the 6.5-meter Magellan 1 Baade Telescope at Las Campanas Observatory resulting in deep photometry down to V ~ 24 mag. By analyzing the color-magnitude diagram for the cluster and utilizing the Victoria-Regina grid of isochrones models we estimated the age of the cluster at ~ 2.25 Gyr and [Fe/H]=-0.71, the numbers which place NGC 2155 outside the age-gap in the age-metallicity relation for LMC clusters. Using the Difference Image Analysis Package (DIAPL), we detected 7 variable stars in the cluster field with variability at the level of 0.01 magnitude in the I-band. Three variables are particularly interesting: two SX Phoenicis (SX Phe) stars pulsating in the fundamental mode, and a detached eclipsing binary which is a prime candidate to estimate the distance to the cluster.