Optical observations of star clusters NGC 1513 and NGC 4147; white dwarf WD 1145þ017 and K band imaging of star-forming region Sh 2-61 with the 3.6-m Devasthal optical telescope

Abstract

The UBVRI CCD photometric data of open star cluster NGC 1513 are obtained with the 3.6-m Indo-Belgian Devasthal optical telescope (DOT). Analyses of the GAIA EDR3 astrometric data have identified 106 possible cluster members. The mean proper motion of the cluster is estimated as la cos d ¼ 1:29 0:02 and ld ¼ 3:74 0:02 mas yr1. Estimated values of reddening EðB VÞ and distance to the NGC 1513 are 0:65 0:03 mag and 1:33 0:1 kpc, respectively. Age of 225 25 Myr is assigned to the cluster by comparing theoretical isochrones with deeply observed cluster sequences. Using observations taken with the 3.6-m DOT, values of distance and age of the galactic globular cluster NGC 4147 are estimated as 18:2 0:2 Kpc and 14 2 Gyr, respectively. The optical observations of planetary transit around white dwarf WD 1145þ017 and K-band imaging of star-forming region Sharpless Sh 2-61 demonstrate observing capability of 3.6-m DOT. Optical and near-infrared observations of celestial objects and events are being carried out routinely with the 3.6-m DOT. They indicate that the performance of the telescope is at par with those of other similar telescopes located elsewhere in the world. We, therefore, state that this observing facility augurs well for multi-wavelength astronomy including the study of astrophysical jets.