11 items with the tag “supernova

  • Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks
    NAI 2009 Arizona State University Annual Report

    Supernova-generated material can affect the evolution of a solar system when supernova ejecta enter protoplanetary disks. We are particularly interested in the injection of 26Al, a short-lived radioactive isotope that can affect the delivery of water to Earth-like planets when they are formed. In this task, we are conducting numerical calculations to model such injections in our Solar System, and to understand the consequences for oxygen isotope compositions that can be measured in meteorites.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds
    NAI 2009 Arizona State University Annual Report

    The influence of supernova-generated material on the evolution of a solar system depends on the effectiveness with which supernova ejecta can enter the molecular clouds from which solar systems are formed. In this task, we are using computational codes to model the injection of supernova-generated material.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars
    NAI 2009 Arizona State University Annual Report

    In order to understand the distribution of elements both on the scale of the Galaxy and individual solar systems we must understand the production of elements in stars and the dispersal of newly synthesized elements in supernova explosions. We are especially interested in the production and distribution of the radioactive isotope 26Al because the amount of this element present in the early Solar System may have affected the heating of planetesimals and hence their ability to retain water and deliver it to early planets. This task uses computational models of stellar evolution and supernovae with the most accurate treatments of physics available to predict the production elements by individual stars and by populations of stars over time.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars
    NAI 2010 Arizona State University Annual Report

    Massive stars are the primary source for the elements heavier than hydrogen and helium on the periodic table. We are simulating the evolution of these stars and their eventual deaths in supernova explosions with state of the art physics in order to generate the most accurate estimates possible of the yields of chemical elements from both individual stars and stellar populations. We are also observing the variations of elemental abundances in nearby planet host candidates in order to determine the range of variation in bioessential elements and the effects of non-sunlike compositions on the evolution of the host stars.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks
    NAI 2010 Arizona State University Annual Report

    The goal of this task is to determine how much supernova material can make its way into a forming solar system, after the star has formed and is surrounded by a protoplanetary disk. This supernova material may contain radioactive isotopes like 26Al, which is the primary mechanism by which asteroids melted and which may control delivery of water and other elements to terrestrial planets. This supernova material may also change the abundance ratios of bioessential elements.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds
    NAI 2010 Arizona State University Annual Report

    The goal of this task is to determine how much supernova material can make its way into a forming solar system during its initial stages, when the gas that will form the star and the planets are collapsing from a molecular cloud. This supernova material may contain radioactive isotopes like 26Al, which is the primary mechanism by which asteroids melted and which may control delivery of water and other elements to terrestrial planets. This supernova material may also change the abundance ratios of bioessential elements.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 4: Model the Injection of Supernova Material Into Protoplanetary Disks
    NAI 2011 Arizona State University Annual Report

    Our Solar System is known to have contained short-lived radionuclides such as 26Al and 60Fe when it formed. These must have been created either during or just before Solar System formation. A supernova explosion is thought to be the most likely source. Depending on the manner of supernova injection, other elements relevant to life may accompany the radionuclides. In this task we study how a supernova might inject material into the protoplanetary disk from which the planets in the Solar System formed, after the formation of the protostar. This tests the hypothesis of supernova injection and quantifies its contributions to radionuclides and other elements.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds
    NAI 2011 Arizona State University Annual Report

    Our Solar System is known to have contained short-lived radionuclides such as 26Al and 60Fe when it formed. These must have been created either during or just before Solar System formation. A supernova explosion is thought to be the most likely source. Depending on the manner of supernova injection, other elements relevant to life may accompany the radionuclides. In this task we study how a supernova might inject material into the molecular cloud from which the Solar System formed, before formation of the protostar. This tests the hypothesis of supernova injection and quantifies its contributions to radionuclides and other elements.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars
    NAI 2011 Arizona State University Annual Report

    The elemental ratios in stars and their planets will differ because each star has a different contributions from sources of stellar nucleosynthesis. The dominant contributions of heavy elements to molecular clouds come from supernova explosions, which may also contribute material just prior to star formation. To quantify what elements might be contributed by supernovae, in this task we first perform numerical simulations of stellar evolution, predicting how stellar properties (e.g., luminosity, temperature, internal composition, stellar winds, etc.) change over time. These results are made available to the public. We then simulate the explosions of massive stars as supernovae, to determine what elements are ejected. As a complementary study, we are also using spectra of stars, obtained during radial velocity planet searches, to find the chemical abundances of hundreds of nearby, potentially habitable stars, to assess the variability of starting compositions, and we are also modeling how the habitable zones of stars with these starting compositions might vary over time.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 3: Model the Injection of Supernova Material Into Star-Forming Molecular Clouds
    NAI 2012 Arizona State University Annual Report

    The goal of this task is to see if material ejected from a star that has exploded as a supernova can make its way into the gas as it is forming new solar systems. It has been expected that this material, because it is moving so fast (> 2000 km/s) when it hits the cold, dense molecular cloud in which stars are forming, would shock, heat up, and then “bounce” off of the cloud boundary. Our numerical modeling using state-of-the-art numerical codes and thousands of computers at the Arizona Center for Advanced Computing, shows that the gas can in fact cool quickly enough to penetrate into the molecular cloud. Stars can be contaminated with supernova material just as they are forming, at contamination levels consistent with isotopic and chemical evidence from meteorites.

    ROADMAP OBJECTIVES: 1.1 3.1
  • Astrophysical Controls on the Elements of Life, Task 2: Model the Chemical and Dynamical Evolution of Massive Stars
    NAI 2012 Arizona State University Annual Report

    Stars create the chemical elements heavier than hydrogen and helium, with the majority arising from the lives and violent deaths of massive stars in supernova explosions. The starting chemical composition of stars also affects their evolution and that of their associated planets. We have performed computational simulations for a large range of stellar masses to provide predictions for important stellar characteristics (i. e. brightness, temperature, stellar winds, composition) over the stars’ lifetimes and made the data available to the public. We have also simulated the explosions of massive stars to predict the chemical abundances of material ejected from the dying stars and how that material is distributed in the surrounding universe. As a complement, we are finding the chemical abundances of hundreds of nearby, potentially habitable stars and modeling how the habitable zones and planets of stars with different abundances evolve.

    ROADMAP OBJECTIVES: 1.1 3.1