Optical Observations of star clusters NGC 1513 and NGC 4147; white dwarf WD1145+017 and $K$ band imaging of star forming region Sh2-61 with the 3.6 meter Devasthal Optical Telescope

Abstract

The U BVRI 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 µ α Cosδ = 1.29 ± 0.02 and µ δ = −3.74 ± 0.02 mas yr −1 . Estimated values of reddening E(B − V) and distance to the NGC 1513 are 0.65±0.03 mag and 1.33±0.1 kpc respectively. An age of 225 ± 25 Myr is assigned to the cluster by comparing theoretical isochrones with deep observed cluster sequence. 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 WD1145+017 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 study of astrophysical jets.