Show Notes: May 7th, 2013 UTC
Hosts: Ryan, Paul, Jesse
Title: Burping Betelgeuse and Cosmic Ray
Podcast to Come! Show notes are below.
This week in space/astronomy history:
2. May 6, 1975 – NASA announces Canada to build the Shuttle Robot Arm (article)
3. May 9, 2003 – Hyabusa is launched – first retrieval mission to asteroid (Itokawa)
1. 60 cm telescope mirror aluminized and ready to return to service tomorrow!
2. The Star Spot Episode 29: The Search for Extraterrestrial Intelligence, with
Seth Shostak. Listen at their website here.
3. Music Monday – Cmdr Chris Hadfield (@Cmdr_Hadfield) sings ‘Is Somebody Singing’ with the schools/science centres across the country.
4. Teaser for Jeremy Hansen interview and Chris Hadfield’s Return – Next week’s Show – Ryan.
Major Topics Discussed:
1. Interview with Ray Bielecki for May 25 ‘What’s up in Space’ event
2nd Annual What’s up in Space? webpage
2. Betelgeuse is burping
Betelgeuse (pronounced BAY-tel-jewz) is the 2nd brightest star in the constellation Orion (8th in the sky), marking the left shoulder of the great hunter, it is 640 ly away. It is often easy to pick this star out from the crowd due to its very characteristic red colour. This is because Betelgeuse is a class of star known as a Red Supergiant. In size, Betelgeuse is approximately 600 solar radii, or ~3.0A.U (the star may even reach up to 5.0 A.U., which would be roughly equivalent to the size of Jupiter’s orbit). The precise diameter is hard to measure, as red giant stars don’t have as clearly defined as surface as our sun does. The stars surface blends into its atmosphere, and then into space gradually.
Red giant stars have mostly used up their main fuel source, Hydrogen, and have begun fusing Helium into Carbon and Oxygen, and eventually will fuse other elements as well. Eventually, when Betelgeuse is no longer able to fuse anything, its internal support system will collapse leading to a type II supernova. This will yield not only a massively impressive light show in the sky, but also a neutron star or a black hole.
Using the new eMERLIN radio telescope in England (run from Jodrell), astronomers have taken some images of Betelgeuse, with some surprising results. Its clear that the radio waves originate from a much larger surface area than the optical image (a full 5 times larger). The image also shows two major ‘hot spots.’
The telescope also observed a massive arch of gas containing ⅔ the mass of Earth, this arc stretches out to almost Neptune’s orbit. This may be part of the natural process Red Giant’s go through, where they shed the outer parts of their atmosphere.
3. Brightest cosmic ray blast ever seen imaged by Fermi
The Fermi space telescope has imaged the brightest cosmic ray burst ever seen, 3.6 billion light years from Earth, in the constellation Leo. This particular burst is 3 times more energetic than any other gamma ray burst recorded by Fermi’s Large Area Telescope. Not only was the burst the most energetic ever recorded but it was the longest in duration ever recorded. One particular gamma ray was recorded with an energy of 94 billion electron volts.
The burst lasted for hours, long enough that ground based telescopes were able to tune in and gather data even as Fermi was still recording the event. No two bursts are the same, however they are usually classed as short or long depending on their duration, though even the long bursts last between 2 seconds and several minutes nonetheless two hours.
Astronomers think that most gamma ray bursts occur when massive stars run out of nuclear fuel and collapse under their own weight. As the core collapses into a black hole, jets of material shoot outward at nearly the speed of light. Another possibility is the collision of two pulsars, but this was ruled out as pulsar collisions usually result in short bursts. Since this GRB was within the top 5% of bursts in terms of closeness to Earth, its expected that an associated supernova explosion will emerge shortly. Tracing a supernova explosion in the area will give us an idea of the origin of the burst.
Where In The Universe:
Last weeks Image: http://yorkuniverse.com/wp-content/uploads/2013/04/WITU_ep151.jpg
Answer: Crab Nebula
Winner: Alfred Ferwerda
This weeks Image: http://yorkuniverse.com/wp-content/uploads/2013/05/WITU_ep152.jpg
Thanks for listening!
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