Scientists at Aryabhatta Research Institute of Observational Sciences (ARIES) in Uttarakhand's Nainital district have discovered 28 new variable stars in Milky Way galaxy. The team performed photometric observations of globular cluster 'NGC 4147' using Devasthal Optical Telescope (DOT), former ARIES director Anil Pandey said. Variable stars have been found for the first time in NGC 4147, he added.