Ephemeris for Monday, September 16th. Today the Sun will be up for 12 hours and 29 minutes, setting at 7:51, and it will rise tomorrow at 7:23. The Moon, 2 days past full, will rise at 9:21 this evening.
When a star explodes in a supernova due to being very massive, it generally leaves a tiny compact remnant called a neutron star or a black hole within an expanding cloud of gas and dust. However in the early universe there was only hydrogen and helium. It turns out that stars could get much more massive, maybe several hundred times the mass of the Sun, rather than tens of times more massive that the Sun that exist now. Theoreticians suggest that when these stars explode, there was no core to collapse into a black hole or neutron star, but the whole star ignites in a thermonuclear reaction spewing its entire self, and newly created elements into the universe. Astronomers are studying a supernova suspect discovered in 2016: SN 2016iet.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
The discovery image (right) shows SN 2016iet and its most likely host galaxy. ...