IT'S an embarrassing gap in astronomers' knowledge. Despite relying on type Ia supernovae as tools to measure the dark energy speeding up the universe's expansion, they still don't know exactly what causes the blasts. Now the picture has got even fuzzier.
In the standard scenario, a white dwarf pulls matter from a companion star, and this extra mass triggers a supernova. Heavy white dwarfs were thought more likely to explode, since it takes less to push them over the edge.
Now Christopher Pritchet of the University of Victoria in British Columbia, Canada, and colleagues have observed galaxies dominated by lightweight white dwarfs producing type Ia supernovae just as efficiently as those dominated by heavier white dwarfs. These cases may be down to the collision of two white dwarfs, says co-author Andrew Howell of the University of Toronto. The study will appear in The Astrophysical Journal Letters.
Cosmology - Keep up with the latest ideas in our special report.
By M Lyne
Thu Jul 03 22:33:46 BST 2008
The lighter dwarves be pulling in heavier matter streams or faster flows?By John Smith
Sat Jul 05 23:32:26 BST 2008
Crystalline spheres ...By Jimmy James
Sun Jul 06 06:09:00 BST 2008
This comment has been found to be in breach of our terms of use and has been removed.REPORT | REPLY
By Bob Meyer
Sun Jul 06 19:05:05 BST 2008
Associate mater, electricity, fluid dynamics and gravity already. Adding mass is the same as adding charge to a capacitor. And don't get me started on Vortex's vs. Magnetic Field Eddies vs. Black Holes. Capacitors discharge at a set charge level as do stars. Gravity is like the resistance of a charge heading to ground, The more charge the higher the resistance the more it pulls the ground toward the charge. Ain't nothing free and nothing empty.All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.
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18:00 07 October 2008
17:56 07 October 2008
