Using James Webb Space Telescope to study supernovae as source of heavy elements in the universe

In 1980’s well-liked e book “Cosmos,” Carl Sagan wrote of what makes us: “All the weather of the Earth besides hydrogen and a few helium have been cooked by a form of stellar alchemy billions of years in the past in stars, a few of that are immediately inconspicuous white dwarfs on the opposite facet of the Milky Way galaxy. The nitrogen in our DNA, the calcium in our enamel, the iron in our blood, the carbon in our apple pies had been made within the interiors of collapsing stars. We’re fabricated from ‘starstuff.'”

Chris Ashall, an assistant professor of astrophysics within the Virginia Tech School of Science’s Division of Physics, desires to know extra about the place and the way this “starstuff” is made.

This week, Ashall started utilizing NASA’s James Webb House Telescope to gather knowledge on the presence of heavy components in exploding dying stars, or supernovae. As James Webb’s Baltimore-based mission operations middle relays instructions to the distant telescope to assemble observations on supernovae focused by Ashall, his crew at Virginia Tech will examine the collected knowledge alongside greater than 30 different scientists from world wide as a part of the Mid-Infrared Supernova Collaboration that Ashall leads.

Ashall is among the few scientists chosen to make use of the telescope for 2 initiatives through the mission’s first cycle. The initiatives will examine two varieties of supernovae: sort Ia supernovae, which describe exploding carbon-oxygen white dwarf stars, and core-collapse supernovae.

“Just about the whole lot round us comes from dying stars,” Ashall mentioned. “We’re fabricated from stardust. With the ability to examine that reality—what we’re made out of—intimately, and to grasp the place the weather round us come from, is actually wonderful.”

Stars produce heavy components by the method of stellar nucleosynthesis. As stars burn, die, and explode, thermonuclear reactions happen inside them.

Supernovae are one of many highest-temperature and highest-density locations within the universe, Ashall mentioned. The fabric in stars burns and burns to type heavier and heavier elements, from hydrogen to helium, helium to carbon, carbon to oxygen, and so forth, during the Periodic Desk to iron.

When the celebrities lastly explode, they throw all of this materials again out into the universe at speeds as much as 30 % of the velocity of sunshine to make the subsequent technology of stars and planets. “That is how the planet and the whole lot round us can have all of those heavy components,” Ashall mentioned. “They had been made in dying stars.”

It is broadly accepted that many of the heavy components within the universe are made by means of stellar nucleosynthesis, however Ashall desires to know extra—to hint explicit components to the forms of supernovae on the market and to measure at what ranges these components are made by the celebrities.

In his first mission, Ashall will search for components generally discovered on Earth, reminiscent of manganese, chromium, cobalt, and nickel, by focusing the James Webb Telescope on one Ia supernova specifically: a third-generation white dwarf titled SN2021aefx, which exploded a yr in the past within the spiral galaxy NGC1566, also called the Spanish Dancer.

“A yr after it has exploded, you possibly can look and see proper by to the middle of the supernova,” Ashall mentioned. “That is the place all this high-density burning occurs. The nucleosynthesis occurs in only some seconds, however we see the central high-density area a yr after the explosion.”

Ashall will use the telescope to gather imaging and spectroscopy knowledge on components inside SN2021aefx. Spectroscopy entails taking a look at spectra produced by materials when it interacts with or emits gentle by breaking the sunshine into its part colours, per NASA. “Spectroscopy tells us about completely different elemental traces,” Ashall mentioned. “If there is a line, we all know the factor is there.”

NASA’s new telescope is the primary that is able to gathering the form of knowledge Ashall wants. James Webb can observe in wavelength regimes that Hubble simply could not, Ashall mentioned.

“Hubble may primarily observe within the ultraviolet, optical, and a tiny bit within the near-infrared, however James Webb was made to look at within the near-infrared and the mid-infrared,” he mentioned. “It opens up a complete new wavelength window to do astrophysics.”

Ashall’s second mission will concentrate on detecting carbon monoxide and silicon monoxide, additionally constructing blocks for all times within the universe, in core-collapse supernovae. Core-collapse supernovae are huge dying stars greater than eight instances the mass of our sun. The supernova’s identify comes from the form of explosion that happens, Ashall mentioned: When the huge star dies, it collapses in on itself and makes an explosion greater than 100 billion instances brighter than the sun.

Utilizing the observations made by the James Webb House Telescope, Ashall will work to not solely supply heavy components, however to research after they had been ejected by the exploding supernova. His crew will examine how supernovae explode by pairing the information with laptop simulations of explosions.

“Once we measure these traces, we will work out velocities of the explosion,” Ashall mentioned. “So then we’ll perceive how briskly these components are thrown out into the universe.”

Beginning with the one sort Ia supernova, Ashall hopes to construct a pattern of various forms of supernovae to supply significant statistics on their position as element-makers. He is open to no matter they’re going to discover.

“If we do not discover these components coming from supernovae, then we’ve to reassess what we find out about how stars die and the way these components are launched into the universe,” Ashall mentioned. “It is fascinating both means.”