This category of supernova called "Type Ia" generates many of the elements around us but the mechanism that sets off a Type Ia supernova
explosion has remained elusive, Xinhua news agency reported.
A white dwarf star exploded as a Type Ia supernova
over 11 million years ago and a shell of light from it is expanding and sweeping through interstellar space, NASA's Hubble Space Telescope has found.
Among the topics are precision observational asteroseismology using Kepler spacecraft data, updates on the pulsating sdB star Feige 48 through spectroscopy, glimpses into the secret lives of hot subdwarf stars, tidally enhanced stellar wind in binaries as a second parameter for the horizontal branch morphology of globular clusters, hot subdwarf stars as the donors of type Ia supernova
progenitors, and a radial velocity survey of hot subdwarfs with main sequence companions using the Hobby-Eberly telescope.
Astronomers are now discovering about 1,000 per year, and Type Ia supernova
observations are now calibrated to build the extragalactic distance scale.
Type Ia Supernova
Rates in Intermediate Redshift Galaxy Clusters
The team made this discovery as part of a wider study of a particular type of supernova known as a Type Ia supernova
. These occur when a carbon-oxygen white dwarf star explodes suddenly due to activity of a binary companion.
When it grows to 1.4 solar masses this way, the star's entire bulk explodes in a carbon-fusion reaction as a Type Ia supernova
. If T Pyx did that anytime soon, it would shine at magnitude--9, a hundred times brighter than Venus.
This factor leads to an explanation of type Ia supernova
measurements without dark energy.
Despite their importance, the actual mechanism that triggers a Type Ia supernova
explosion has remained elusive for decades.
Combining this observation with another chance observation by a Japanese amateur astronomer, Filippenko's team was able to calculate that SN 2014J had unusual characteristics-it brightened faster than expected for a Type Ia supernova
and, even more intriguing, it exhibited the same unexpected, rapid brightening as another supernova that KAIT discovered and imaged last year-SN 2013dy.
In this study, we analytically derive the turning point redshift only from the cosmological model without combining the model with the type Ia supernova
data of measurements and thus without using the approximate redshift-luminosity distance relation.