Cottrell Scholar Awards - 2017
The Physical Drivers of Diversity in Nova Explosions
A white dwarf star is basically what’s left after a normal star has exhausted its nuclear fuel. Incredibly dense, it is prevented from total collapse by electron degeneracy pressure, the force that occurs when electrons in atoms are squeezed too closely together.
But if the white dwarf is composed of primarily carbon and oxygen atoms and is accreting, or collecting, matter from a nearby sister star, eventually it may reignite and trigger one of the most incredible explosions in the universe, a Type Ia supernova. Supernovae are the major source of elements heavier than oxygen in the universe and their remnants play an important role in subsequent star formation. Understandably, astronomers and astrophysicists want to know more about how these intense explosions occur.
“Classical novae -- thermonuclear explosions on white dwarfs -- hold immense potential for understanding Type Ia supernova progenitors and as laboratories for shock physics and particle acceleration,” according to Laura B. Chomiuk, astronomy, Michigan State University. (The primary difference between a nova and a supernova is the strength of the explosion.)
Chomiuk has received a prestigious Cottrell Scholar Award from Research Corporation for Science Advancement (RCSA) to develop a systematic multi-wavelength observational program that measures both fundamental novae explosion parameters and links them to the physical mechanisms that give rise to various types of stellar explosions, including the Type Ia supernova.
Specifically, she hopes to establish and analyze the first-ever complete sample of galactic novae; to increase the sample of novae with well-measured ejecta masses, white dwarf masses, and accretion rates by a factor of 10, testing theoretical predictions of accreting white dwarfs; and to measure the contribution of shocks to the energy budget of 40 novae and determine the efficiency of relativistic particle acceleration.
There is also an educational component to the Cottrell Scholar Award. Chomiuk, who is also director of the MSU Campus Observatory, intends to use some of the funding, as well as the Observatory’s facilities and data, to refine an undergraduate course in observational astronomy into a learning experience that is more experiential, student-driven and inquiry-based, and to provide research experiences to a large number of MSU undergraduates, focusing on those from under-represented groups.