While on Earth dust may mostly seem like a housecleaning nuisance, in the far reaches of space, it plays an exciting role in galaxy research. Although the existence of dust in space continues to be surrounded by intrigue, an international team of astronomers recently identified a type Ia supernova creating cosmic dust.
A new study published in Nature Astronomy highlighted this previously unknown source of cosmic dust. Prior to the study, dust formation has been observed in supernovae, but only in core-collapse supernovae that occur when a massive star explodes.
"The origins of cosmic dust have long been a mystery. This study marks the first detection of a significant and rapid dust formation process in the thermonuclear supernova interacting with circumstellar gas," said first author Wang Lingzhi, from the South America Center for Astronomy of the Chinese Academy of Sciences, in a press release.
Observing a Type Ia Supernova
These types of supernovae don’t occur in elliptical galaxies, which have a different shape than spiral galaxies (like our galaxy, the Milky Way) and contain mostly older stars. The origin of dust in elliptical galaxies, therefore, has perplexed astronomers until this point.
Researchers now believe they have found an answer; much of the dust in elliptical galaxies likely emerges from thermonuclear Type Ia supernovae — the explosion of white dwarf stars in binary systems with another star.
This knowledge came to light as the research team spent three years monitoring a supernova (SN 2018evt) via multiple observatories, including NASA’s Spitzer Space Telescope and the Las Cumbres Observatory Global Telescope Network.
The team observed the supernova colliding with material cast off by one or both stars in the binary system before the white dwarf star exploded; a shock wave was then sent into the pre-existing gas.
The light emitted by the supernova became dim in the wavelengths our eyes can perceive, but then glowed brighter in infrared light. This meant that dust was being produced in the nearby gas, which cooled after the supernova shock wave passed through it.
Researching Cosmic Dust
The amount of dust created by the supernova is estimated to equal more than 1 percent of the Sun’s mass. The dust will further proliferate, potentially capable of increasing tenfold as the supernova cools.
"This study offers insights into the contribution of thermonuclear supernovae to cosmic dust, and more such events may be expected to be found in the era of the James Webb Space Telescope," said Wang Lifan from Texas A&M University, a co-first author of the study, in a release.
"The creation of dust is just gas getting cold enough to condense," said Andy Howell from Las Cumbres Observatory and the University of California Santa Barbara. "One day that dust will condense into planetesimals and, ultimately, planets. This is creation starting anew in the wake of stellar death. It is exciting to understand another link in the circle of life and death in the universe."
Although this process of dust creation is still not as abundant or efficient as core-collapse supernovae in spiral galaxies, it could explain how the majority of dust in elliptical galaxies manifests.
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review them for accuracy and trustworthiness. Review the sources used below for this article:
NASA. Types of Galaxies.
NASA. Type Ia Supernova.