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Supernova Discovery

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Supernova Light Curve

Stellar Astrophysics and Dark Energy

Another way to look at the fundamental processes in nature is to look at the very large scale in cosmology. Dark energy is an energy or interaction that we do not yet understand, but which appears to be propeling the universe to expand at ever faster rates. Remarkably, dark energy totals 70% of the universe's total energy! I study dark energy primarily by preparations of a new project called the Dark Energy Spectroscopic Instrument (DESI). This instrument will obtain the light spectrum, like to rainbow of colors produced by sunlight thru a prism, of 5000 galaxies at a time over a five yearr period. These spectra, which will number in the 10's of millions, will map out the distribution of matter in the universe and detect with exquisite precision the ringing echo of the Big Bang.

As we plan for DESI, I have also been involved in the study of supernovae and gamma-ray bursts. These are two class of huge explosions that appear to correspond to some stage at the end of a star's life. Supernovae were used in the late 1990's to establish the existence of dark energy. They continue to be a powerful way to understand dark eergy, and provide a strong constraint on our current theories of of the origin of the universe. Currently, I work with SMU graduate students to understand different types of supernovae that may be used to constrain our understanding of dark energy. Here we use SMU's ROTSE-IIIb robotic telescope at McDonald Observatory to discover supernovae, and the Hobby-Eberly Telescope to obtain spectra for them.