The NASA Education and Public Outreach group is based in Northern California at Sonoma State University, and is part of the Physics and Astronomy Department. The group is led by Professor Lynn Cominsky, who is the lead of four NASA funded projects. They have the Education and Public Outreach portion of three different satellite missions: Swift, a gamma-ray burst mission (launched Nov. 2004); XMM-Newton, a joint ESA/NASA X-ray spectroscopy mission (launched Dec. 1999); and GLAST, a general gamma-ray mission (scheduled for launch Dec. 2007). The three NASA projects also each have their own component of the Educator Ambassador program; a master teacher program that trains master teachers to go all around the country to teach the science behind these missions to other educators. The NASA E/PO group also handles the press for the Swift and GLAST missions… but today we will be concentrating on science of the GLAST and XMM-Newton missions.
SN1987A before and after image from Anglo-Australian Observatory. It’s in a companion galaxy to the Milky Way called the Large Magellanic Cloud, 160,000 light-years distant. When fusion process no longer produces energy to support the star, the core of the star collapses. With nothing to stop it, the atoms are crushed together, and the infalling material bounces off the superdense core, causing the explosion. A supernova produces about 10 51 erg/s (a billion billion times more than the sun). The supernova disperses the elements it has created. In addition, the energy of the explosion creates elements heavier than iron.
This animation shows the stages of a supernova from the explosion to the expansion of the gas which is called the supernova remnant. This animation is made from stills from the poster that accompanies the SN guide. As it runs, ask them what supernovae have to do with the Earth globe they have. They will say things like, heavy elements in the Earth were made in supernovae, for example. For this presentation, the connection is that neutron stars, the ultra-dense collapsed core of an exploded star, has intense magnetic fields, and the Earth has a magnetic field as well. At this point, you can hand out the magnets and staples for them to put in the Earth balls.
Very briefly go over the fact that only high mass stars – more massive than the Sun – can explode. Stars from very roughly 8 – 20 times the mass of the Sun explode and leave a neutron star in the star, which can become a pulsar, a spinning neutron star with a strong magnetic field. More on these later…
NASA: Supernova <ul><li>Janet Moore </li></ul><ul><li>NASA Educator Ambassador </li></ul>NSTA Cincinnati
The NASA E/PO Program at Sonoma State University <ul><li>A group of people working collaboratively to educate the public about current and future NASA high energy astrophysics/astronomy missions. </li></ul><ul><li>Led by Prof. Lynn Cominsky </li></ul>Swift Fermi (GLAST) XMM-Newton
Stellar evolution made simple Stars like the Sun go gentle into that good night More massive stars rage, rage against the dying of the light Puff! Bang! BANG! 0.077 ~8 M o ~8 ~20 M o ~20 ~100 M o
Rare Look at a Supernova XRT UVOT Swift Images of NGC 2770 2008 January 7:00 UT
Rare Look at a Supernova Swift Images of NGC 2770 XRT UVOT 2008 January 9:00 UT
<ul><li>Three Supernova Activities </li></ul><ul><li>Fishing for Supernovae </li></ul><ul><li>Crawl of the Crab </li></ul><ul><li>Magnetic Poles and Pulsars </li></ul><ul><li>Three Supernova Activities </li></ul><ul><li>Fishing for Supernovae </li></ul><ul><li>Crawl of the Crab </li></ul><ul><li>Magnetic Poles and Pulsars </li></ul>Crawl of the Crab
Crawl of the Crab We will use two pictures of the Crab Nebula 1956 1999 Crab Pulsar
Measuring Expansion Gives Age <ul><li>Assume pulsar remains at center of nebula </li></ul><ul><li>Knots came from star, were blown out by the supernova, and travel at a constant velocity in a constant direction </li></ul><ul><li>If we can calculate that velocity, we can calculate how long to get from the star to the “current” location </li></ul>
Measuring Expansion Gives Age <ul><li>- OR - </li></ul><ul><li>Use one of the knots to make a proportion! </li></ul><ul><li>Distance in 43 years = Total Distance </li></ul><ul><li> 43 (years) Total Time </li></ul>
So, let’s get started! <ul><li>Packet </li></ul><ul><li>Rulers </li></ul><ul><li>Calculators </li></ul><ul><li>Do NOT do graphing part </li></ul><ul><li>Each group choose ONE knot to make calculations from </li></ul>
Your Results According to your calculations, in what year did the supernova occur? Why might we get different answers for different knots? How might you use this in your classroom?