Comet reveals solar magnetic field details

BBC : Comet Lovejoy dove deep into the Sun’s atmosphere in 2011 and surprised astronomers when it emerged from the other side (before then disintegrating). Images of the event have provided astronomers with an unprecedented look at the magnetic field within the Sun’s corona. Lovejoy approached the Sun at 600 km/s and experienced megakelvin temperatures. Astronomers using NASA’s Solar Dynamics Observatory and Japan’s Hinode spacecraft observed that the comet’s tail didn’t follow the normal trajectory away from the head. Instead it got locked into a different path by the solar magnetic field and moved back and forth as the field fluctuated. The magnetic field’s fluctuations are one of the sources of solar winds and flares, and the chance to observe its behavior in the corona is a rare one. No instruments that scientists could create would be able to survive long enough to provide any data from inside the corona. Each sun-grazing comet like Lovejoyâmdash;1600 have been observed, but Lovejoy was the first to reappearâmdash;serves as an indirect way of studying the corona. The next is expected by the end of 2013.