Waspie_Dwarf Posted March 5, 2014 #1 Share Posted March 5, 2014 Critical mass not needed for supernova explosions Astronomers searching for clues about dark energy, the mysterious force that is speeding up the expansion of the Universe, have uncovered new evidence about the nature of supernovae, finding many are lighter than scientists had expected.The findings, from an international team from the Nearby Supernova Factory project, overturn previous understanding of white dwarf stars and raise new questions about how these stars explode. Read more... Link to comment Share on other sites More sharing options...
Taun Posted March 5, 2014 #2 Share Posted March 5, 2014 I have a question Waspie... How does the dark matter accelerate the expansion? Does it "repel" non-"dark" matter? 1 Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted March 5, 2014 Author #3 Share Posted March 5, 2014 I have a question Waspie... How does the dark matter accelerate the expansion? Does it "repel" non-"dark" matter? It's not dark matter they are talking about, it's dark energy. As to the part it plays in a Type Ia Supernova explosion... I don't have the foggiest idea. 1 Link to comment Share on other sites More sharing options...
Taun Posted March 5, 2014 #4 Share Posted March 5, 2014 Thanks... I missed the distinction in the article... Link to comment Share on other sites More sharing options...
spacecowboy342 Posted March 5, 2014 #5 Share Posted March 5, 2014 So much for having a standard candle to give us distances to galaxies Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted March 5, 2014 Author #6 Share Posted March 5, 2014 So much for having a standard candle to give us distances to galaxies I'm not sure that this discovery will affect that adversely. Link to comment Share on other sites More sharing options...
spacecowboy342 Posted March 5, 2014 #7 Share Posted March 5, 2014 I'm not sure that this discovery will affect that adversely. You probably know a lot more about this than I do, but how can we be sure how far away a galaxy is if we can't be sure whether the standard candle is truly "standard"? Link to comment Share on other sites More sharing options...
Waspie_Dwarf Posted March 19, 2014 Author #8 Share Posted March 19, 2014 You probably know a lot more about this than I do, but how can we be sure how far away a galaxy is if we can't be sure whether the standard candle is truly "standard"? Sorry it's taken me so long to reply. I looked up the information so that I could give you a correct reply and then forgot all about it. The reason that these are used as standard candles is that there is a relationship between the colour and speed at which they fade and their brightness. Measuring the colour, timing the fading and measuring the apparent brightness as seen by us on Earth enables you to calculate distance to the supernova with an accuracy of about 10%. This relationship is based on observational evidence, this new discovery does not change that. This Berkeley Lab article gives more details: Standard-Candle Supernovae are Still Standard, but Why? 1 Link to comment Share on other sites More sharing options...
spacecowboy342 Posted March 19, 2014 #9 Share Posted March 19, 2014 Thanks Link to comment Share on other sites More sharing options...
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