quarta-feira, 26 de abril de 2017

Astronomy picyure of the day - 2017 April 25 - A Split Ion Tail for Comet Lovejoy E4

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A Split Ion Tail for Comet Lovejoy E4 
Image Credit & Copyright: Fritz Helmut Hemmerich
Explanation: What's happened to Comet Lovejoy? In the pictured image, a processed composite, the comet was captured early this month after brightening unexpectedly and sporting a long and intricate ion tail. Remarkably, thetypically complex effect of the Sun's wind and magnetic field here caused the middle of Comet Lovejoy's ion tail to resemble the head of a needle. Comet C/2017 E4 (Lovejoy) was discovered only last month by noted cometdiscoverer Terry Lovejoy. The comet reached visual magnitude 7 earlier this month, making it a good target for binoculars and long duration exposure cameras. What's happened to Comet Lovejoy (E4) since this image was taken might be considered even more remarkable -- the comet's nucleus appeared to be disintegrating and fading as it neared its closest approach to the Sun two days ago.