VR CCD photometry of variable stars in globular cluster NGC 4147. (arXiv:1905.08249v1 [astro-ph.SR])

VR CCD photometry of variable stars in globular cluster NGC 4147. (arXiv:1905.08249v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lata_S/0/1/0/all/0/1">Sneh Lata</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pandey_A/0/1/0/all/0/1">A. K. Pandey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pandey_J/0/1/0/all/0/1">J. C. Pandey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yadav_R/0/1/0/all/0/1">R. K. S. Yadav</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pandey_S/0/1/0/all/0/1">Shashi B. Pandey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gupta_A/0/1/0/all/0/1">Aashish Gupta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bangia_T/0/1/0/all/0/1">Tarun Bangia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chand_H/0/1/0/all/0/1">Hum Chand</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jaiswar_M/0/1/0/all/0/1">Mukesh K. Jaiswar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_Y/0/1/0/all/0/1">Yogesh C. Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_M/0/1/0/all/0/1">Mohit Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_B/0/1/0/all/0/1">Brijesh Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_T/0/1/0/all/0/1">T. S. Kumar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Medhi_B/0/1/0/all/0/1">Biman J. Medhi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Misra_K/0/1/0/all/0/1">Kuntal Misra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nanjappa_N/0/1/0/all/0/1">Nandish Nanjappa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pant_J/0/1/0/all/0/1">Jaysreekar Pant</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Purushottam/0/1/0/all/0/1">Purushottam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reddy_B/0/1/0/all/0/1">B. Krishna Reddy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sahu_S/0/1/0/all/0/1">Sanjeet Sahu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sharma_S/0/1/0/all/0/1">Saurabh Sharma</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Uddin_W/0/1/0/all/0/1">Wahab Uddin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yadav_S/0/1/0/all/0/1">Shobhit Yadav</a>

We present results of a search for variable stars in a region of the globular
cluster NGC 4147 based on photometric observations with 4k x 4k CCD imager
mounted at the axial port of the recently installed 3.6 m Devasthal optical
telescope at Aryabhatta Research Institute of Observational Sciences, Nainital,
India. We performed time series photometry of NGC 4147 in V and R bands, and
identified 42 periodic variables in the region of NGC 4147, 28 of which have
been detected for the first time. Seventeen variable stars are located within
the half light radius $lesssim$ 0.48 arcmin, of which 10 stars are newly
identified variables. Two of 10 variables are located within the core radius
$lesssim$ 0.09 arcmin. Based on the location in the $V/(V-R)$ colour magnitude
diagram and variability characteristics, 7, 8, 5 and 1 newly identified
probable member variables are classified as RRc, EA/E, EW and SX Phe,
respectively. The metallicity of NGC 4147 estimated from light curves of RRab
and RRc stars with the help of Fourier decomposition is found to be
characteristics of Oosterhoff II. The distance derived using light curves of
RRab stars is consistent with that obtained from the observed $V/(V-R)$
colour-magnitude diagram.

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