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Light Echo around SN 2014J in M82 . Credits NASA , ESA , and Y. Yang (Texas A&M University and Weizmann Institute of Science, Israel). Acknowledgment: M. Mountain (AURA) and The Hubble Heritage Team ( STScI /AURA) Light from a supernova explosion in the nearby starburst galaxy M82 is reverberating off a huge dust cloud in interstellar space. The supernova, called SN 2014J, occurred at the upper right of M82, and is marked by an “X.” The supernova was discovered on Jan. 21, 2014.  The inset images at top reveal an expanding shell of light from the stellar explosion sweeping through interstellar space, called a “light echo.” The images were taken 10 months to nearly two years after the violent event (Nov. 6, 2014 to Oct. 12, 2016). The light is bouncing off a giant dust cloud that extends 300 to 1,600 light-years from the supernova and is being reflected toward Earth. SN 2014J is classified as a Type Ia supernova and is the closest such blast in at least four ...

Spiral Galaxy NGC 253. Credit: ESO Astronomers found a rich molecular reservoir in the heart of an active star-forming galaxy with the Atacama Large Millimeter/submillimeter Array (ALMA). Among eight clouds identified at the center of the galaxy NGC 253, one exhibits very complex chemical composition, while in the other clouds many signals are missing. This chemical richness and diversity shed light on the nature of the baby boom galaxy. Ryo Ando, a graduate student of the University of Tokyo, and his colleagues observed the galaxy NGC 253 and for the first time, they resolved the locations of star formation in this galaxy down to the scale of a molecular cloud, which is a star formation site with a size of about 30 light-years. As a result, they identified eight massive, dusty clouds aligned along the center of the galaxy. “With its unprecedented resolution and sensitivity, ALMA showed us the detailed structure of the clouds,” said Ando, the lead author of the research paper...