Researchers have intently studied the closest type Ia supernova: its proximity to Earth could yield better understanding of this particular type of supernova that astronomers use to gauge distances in the universe and learn about its expansion history. >>Type Ia supernovae (a mere 12M light yrs away) may begin as a carbon/oxygen white dwarf star that feeds off a neighboring normal star. Once the white dwarf star accretes enough material to reach a mass thats 1.4 X the size of our sun compressed into a ball about the size of Earth, it becomes unstable and explodes into a supernova in a process that still isnt fully understood. Because they tend to explode at nearly the same mass and luminosity, they make excellent guides for judging distances. NOTE: Evidence shows this particular supernova may have formed differently.....The lack of pre-explosion detections suggests the supernova may have originated in the merging of compact faint objects, such as 2 white dwarf stars. Until very recently, the leading model for standard candle supernovae was thought to include a companion star from which material was stripped by the white dwarf until the accumulated mass could no longer be sustained by the outwards pressure, leading to a runaway thermonuclear explosion.....The observations of this supernova are challenging for this theoretical picture. Ia supernovae has been used to document the universe not only is expanding but also the expansion process is accelerating. The acceleration phenomenon is called dark energy today.ttu.edu/2014/03/texas-tech-physicist-team-observe-closest-milemarker-supernova-in-generation/
Posted on: Wed, 26 Mar 2014 16:04:49 +0000
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