Show Notes: April 2nd, 2013 UTC
Hosts: Jesse, Paul, Sophia, Ryan (only for curiosity corner)
Special Guest: Dr. Matt Johnson
Title: Dr. Matt planck-ing alongside supernovas
April Fools everyone! The internet was a-buzz with multiple april fools pranks, including the astronauts on the International Space Station. Cmdr Hadfield and company welcomed a new visitor on board! Special guest Dr. Matt Johnson, professor at York University and the Perimeter Institute of Theoretical Physics, helped us understand the Planck data release a little better. It’s 1/100th the normal luminosity of a type 1a supernova, we shall call them ‘mini-supernovae.’ Thanks very kindly to our special guest, and to all you listening.
See below for podcast and show notes.
This Week In Astronomy and Space History:
1. April 1, 1997 – Comet Hale-Bopp reaches Perihelion, dazzling many. One of the more observed Comets of our time.
2. April 1, 1971 – U.S. and Canada ISIS 2 satellite launched to study ionosphere and atmospheric optical emissions; first time images of aurora borealis imaged from above!
3. April 1, 1960 – First known weather observation satellite, TIROS I (Television Infra-Red Observation Satellite), launched into orbit by Thor-Able, and took pictures of Earth’s cloud cover on a global scale. Orbital height: 720 kilometers above until June 29, 1960.
4. April 2, 1845 – First photo of the sun ever taken by Loui Fizeau and Lion Foucault. See NASA link. See National Geographic for image.
Dr. Matthew Johnson from York University/Perimeter Institute.
The Planck Telescope, launched 14 May 2009, has been up in space carefully conducting a very important cosmological experiment. After nearly 4 years of work, the Planck Telescope and its team from the European Space Agency (see the list of 30 papers they published on the experiment!), released the first set of results and research based on the data. We invited Dr. Matthew Johnson, faculty member of York University and the Perimeter Institute for Theoretical Physics, to tell us about the experiment, its findings, and the future of cosmology.
Matt did his Ph.D. at University of California at Santa Cruz, followed by a postdoc at Caltech, followed by a postdoc at the Perimeter Institute before starting his current joint faculty appointment between York University and Perimeter Institute. His research focuses on early universe cosmology, which includes areas ranging from string theory to the Cosmic Microwave Background.
What is the planck telescope, and why was it launched into space?
What is the Cosmic Microwave background, and why is it significant?
What things could Planck do that WMAP couldn’t?
the results, let’s overview the basics major results
Why is this important to the everyday person?
1. Aurora and Meteor in ONE image! From Lake Winnipeg, March 30 2013: Aurora + Meteor image by Shannon Bileski.
2. Hadfield and the ISS play an April Fools Joke. See Hadfields twitter feed. Also the Soyuz docked with the ISS.
3. Curiosity Corner with Ryan Marciniak, on location in Gale Crater.
4. STAR symposium is being re-invigorated! Sophia tells us more.
Major Topics Discussed:
1. New type of supernova discovered: Type Iax supernova (Sophia)
-New type of supernova discovered, less energetic than the type Ia, “mini supernova”
-Supernovae are typically categorized as either:
1) Core-collapse: a star about 10-100 solar masses collapses after fusing elements into iron, left with inert iron core (elements heavier than iron cannot be fused in cores of stars), heating up core to extreme temperatures; collapse is reversed, sending material outward in a supernova explosion (elements heavier than iron are created).
2. Type Ia supernovae: binary systems, a white dwarf (inert C core of dead star) and companion (star or white dwarf.); white dwarf steals mass from companion, accretes on its surface; once mass exceeds limit of ~1.4 solar masses, fusion reignited triggering supernova and destroys white dwarf entirely (a less common event is the merger of two white dwarfs); occur once every 100 yrs per galaxy; standard candles
-type Iax supernova, much dimmer and much less energetic than type Ia supernova.
-Type Iax may not entirely destroy the white dwarf from which it is triggered
-lead author of paper Ryan Foley of the Harvard-Smithsonian Center for Astrophysics called it a “mini-supernova”, “the runt of the supernova litter”
-25 examples of type Iax supernovae were identified; none occurred in elliptical galaxies full of old stars, suggesting that type Iax supernovae occur in young star systems
-findings indicate type Iax supernovae occur in systems with a white dwarf and a helium-dominated companion star, the white dwarf accretes helium from its companion
-finding is new, researchers aren’t certain what triggers type Iax supernovae; helium in outer layer of star may begin to fuse and send shockwaves through white dwarf, or helium accreted may change density of white dwarf and cause explosion
-type Iax supernovae are one-third as common as type Ia, and only one-hundredth as bright (likely the reason none have been observed previously)
-typical supernovae are the most energetic explosions known, so bright they can be seen as far as the edge of the universe (type Ia are brightest)
-strange because the white dwarf at the center is not completely destroyed
-Foley dubs them “a new kind of stellar explosion”
-may give researchers the opportunity to study stellar mass loss as they may occur closer in the cosmic neighborhood
Thanks for listening!
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