Astro Blog

https://www.washingtonpost.com/science/2022/05/11/black-hole-milky-way By Daniel Clery, Science Magazine.   Excerpt: After 5 years, astronomers release picture of Sagittarius A*’s event horizon, ringed by bright gas. Astronomers today released the first image of the supermassive black hole at the center of the Milky Way Galaxy—or at least a picture of its shadow. Eight radio observatories around the globe and more than 300 scientists joined forces to image the object known as Sagittarius A* (Sgr A*), a feat thought impossible until just a few years ago. ...The team, known as the Event Horizon Telescope (EHT), in 2019 produced the  first ever image of a black hole , at the center of the nearby giant galaxy M87. The M87 black hole is 1600 times more massive than Sgr A*. Yet the similarity of the two images—bright rings of gas trapped in death spirals around these ultimate sinkholes—shows how Albert Einstein’s theory of gravity, general relativity, works the same at all scal...

https://www.theguardian.com/science/2022/may/01/catch-a-failing-star-the-tense-wait-for-a-supernova By Robin McKie , The Guardian.  Excerpt: ...When a supernova erupts, it sprays the cosmos with heavy elements – so observing one nearby would provide precious information about the creation of matter in our galaxy. ...Scientists estimate that on average about 20 supernovae occur in a galaxy such as ours every thousand years. Yet only  five have been observed in the last millennium . East Asian and Arabic records indicate there were supernovae in 1006, 1054 and 1181, while European documents recall ones that occurred in 1572 and 1604. ...if supernovae are so brilliant, why have we only detected five in the past 1,000 years? Why have we not seen a number that is nearer the 20 suggested by observations of other galaxies? The answer is straightforward, says Sullivan. “Our galaxy is like a flat plate and our solar system is about two-thirds of the way towards its edge. A supernova th...