Trigger for Milky Way’s Youngest Supernova Identified

NASA | MARCH 31, 2016

Astronomers had previously identified G1.9+0.3 as the remnant of the most recent supernova in our Galaxy. It is estimated to have occurred about 110 years ago in a dusty region of the Galaxy that blocked visible light from reaching Earth.

Supernova G1.9+0.3 Image credit: NASA/CXC/CfA/S. Chakraborti et al.

G1.9+0.3 belongs to the Type Ia category, an important class of supernovas exhibiting reliable patterns in their brightness that make them valuable tools for measuring the rate at which the universe is expanding.

Astronomers use Type Ia supernovas as distance markers across the Universe, which helped us discover that its expansion was accelerating. If there are any differences in how these supernovas explode and the amount of light they produce, that could have an impact on our understanding of this expansion.

Most scientists agree that Type Ia supernovas occur when white dwarfs, the dense remnants of Sun-like stars that have run out of fuel, explode. However, there has been a debate over what triggers these white dwarf explosions. Two primary ideas are the accumulation of material onto a white dwarf from a companion star or the violent merger of two white dwarfs.

The new research with archival Chandra and VLA data examines how the expanding supernova remnant G1.0+0.3 interacts with the gas and dust surrounding the explosion. The resulting radio and X-ray emission provide clues as to the cause of the explosion. In particular, an increase in X-ray and radio brightness of the supernova remnant with time, is expected only if a white dwarf merger took place.

The team also derived a new estimate for the age of the supernova remnant of about 110 years, younger than previous estimates of about 150 years.

YOU MAY ALSO LIKE

In blinding eye disease, trash-collecting cells go awry, accelerate damage

Spider-like cells inside the brain, spinal cord and eye hunt for invaders, capturing and then devouring them. These cells, called microglia, often play a beneficial role by helping to clear trash and protect the central nervous system against infection. But a new study shows that they also accelerate damage wrought by blinding eye disorders, such as retinitis pigmentosa.

Molecule created in Brazil helps fight heart failure

A molecule designed at the Institute of Biomedical Sciences of the University of São Paulo (ICB-USB) may increase the quality of life and life expectancy of people suffering from congestive heart failure.

Eyes of CJD patients show evidence of prions

Scientists have found evidence of the infectious agent of sporadic Creutzfeldt-Jakob disease (CJD) in the eyes of deceased CJD patients. The finding suggests that the eye may be a source for early CJD diagnosis and raises questions about the safety of routine eye exams and corneal transplants.

Asteroid-Hunting Spacecraft Delivers a Second Year of Data

NASA's Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission has released its second year of survey data. The spacecraft has now characterized a total of 439 NEOs since the mission was re-started in December 2013. Of these, 72 were new discoveries.

Methane-eating microorganisms help regulate emissions from wetlands

Though they occupy a small fraction of Earth's surface, freshwater wetlands are the largest natural source of methane emitted into the atmosphere. New research identifies an unexpected process that acts as a key gatekeeper in regulating methane emissions from these freshwater environments.

Fire control harms biodiversity in Brazilian savannah

Policies that prevent fires caused by people in El Cerrado (the Brazilian savannah) lead to biodiversity losses because they promote the expansion of forests with dense vegetation.