NOAO > Observing Info > Approved Programs > 2012A-0556
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NOAO > Observing Info > Approved Programs > 2012A-0556 |
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PI: D. Andrew Howell, Las Cumbres Observatory / University of California Santa Barbara, ahowell@lcogt.net
Address: 6740 Cortona Dr., Santa Barbara, CA 93111, USA
CoI: Mark Sullivan, Oxford University
CoI: Jerod Parrent, Las Cumbres Observatory / Dartmouth College
CoI: Peter Nugent, Lawrence Berkeley National Lab
CoI: Isobel Hook, Oxford University
CoI: Ben Dilday, Las Cumbres Observatory / University of California Santa Barbara
CoI: Kate Maguire, Oxford University
CoI: Melissa Graham, Las Cumbres Observatory / University of California Santa Barbara
Title: Early-time observations of Type Ia supernovae to reveal progenitors
Abstract:
SNe Ia remain nature's best standardized candles, and yet their progenitors
have long been a mystery. However, in a series of three studies this year,
our group has placed the first serious constraints on the progenitors of two
SNe Ia, finding (1) the first hard evidence that the primary is a CO white
dwarf star; (2) in one case the white dwarf is accreting from a mass-losing
evolved secondary and has become a recurrent nova like RS Oph; (3) in another
case a system like RS Oph is ruled out and the companion is probably a main
sequence star. Taken together with our earlier work implicating white dwarfs
mergers in the super-Chandra systems, we are led to the remarkable conclusion
that there are a multiplicity of progenitors for SNe Ia. This may explain our
finding that supernovae in different environments correct to different
absolute magnitudes, and could have serious implications for cosmology. Our
results depend on early-time observations for which the queue-scheduled
Gemini is uniquely suited. We will use these data to rapidly trigger
high-resolution searches for circumstellar material at Keck and VLT, and the
Gemini data will directly probe the unburned progenitor material in the
supernovae themselves.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360
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NOAO > Observing Info > Approved Programs > 2012A-0556 |
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