January 15, 2011
Best Way to Measure Dark Energy Just Got Better
Dark energy is a mysterious force that pervades all space, acting as a "push" to accelerate the Universe's expansion. Despite being 70 percent of the Universe, dark energy was only discovered in 1998 by two teams observing Type Ia supernovae. A Type 1a supernova is a cataclysmic explosion of a white dwarf star.
These supernovae are currently the best way to measure dark energy because they are visible across intergalactic space. Also, they can function as "standard candles" in distant galaxies since the intrinsic brightness is known. Just as drivers estimate the distance to oncoming cars at night from the brightness of their headlights, measuring the apparent brightness of a supernova yields its distance (fainter is farther). Measuring distances tracks the effect of dark energy on the expansion of the Universe.
The best way of measuring dark energy just got better, thanks to a new study of Type Ia supernovae led by Ryan Foley of the Harvard-Smithsonian Center for Astrophysics. He has found a way to correct for small variations in the appearance of these supernovae, so that they become even better standard candles. The key is to sort the supernovae based on their color.
The full article can be found at: http://www.sciencedaily.com/releases/2011/01/110113145054.htm
Posted by rmousigi at January 15, 2011 01:35 PM
Understanding how our universe functions is an important part in understanding how we came to existence and what the future of our universe might be. Dark energy is just another piece of the puzzle that needs to be solved by astronomers and physicists in order to formulate an accurate model of how the universe operates. I thought that it was interesting that astrophysicists were able to deduce the distance of a supernova just by looking at the brightness of the explosion, and from this data they can track the effect that dark energy has on the universe. While dark energy is still very much a mysterious force, it is important the we understand its purpose in our ever expanding universe.
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