After lying dormant for a few months, the Sun is once again witnessing revival of Coronal Mass Ejection (CME) activities since May 5.On May 5, the Sun produced an impressive coronal mass ejection (CME) and a burst of radio emissions, signalling the passage of a shock wave through its outer atmosphere, an alert from NASA said on Thursday.NASA's STEREO-B spacecraft is monitoring an active region hidden behind the Sun's Eastern limb since the big star was spotless for last few months."The activity continued apace on May 6, with at least two more eruptions. The blast site is not yet visible from Earth, but the sun is turning the region toward us for a better view... may be on May 7 and 8," NASA said.Welcoming this renewed activity, after remaining "silent" (without sun spots) for a period of atleast six months, astronomers of Tata Institute of Fundamental Research (TIFR) said, "with the advent of activity, we will be able to get new clues on the delay and also the beginning of a new 11-year-solar cycle, which is due this year."Besides, the shock front propagating or moving away from the Sun will also provide clues to the interplanetary medium, Dr Mayank Vahia of TIFR said.Forecasts in 2006 predicted Cycle 24 to start between late 2007 and early 2008, but new estimates suggested a delay until 2009."The scientists are curious to know whether a new-cycle sunspot was in the offing shortly. For the last few months the Sun was silent and there was no sun spots on it," Vahia said.Scientists have also made some observations on the sun which was silent and the data would be precious, he said."It is always fascinating to study the active Sun," SM Chitre, a former theoretical solar astronomer of TIFR added.