Friday, September 29, 2006

Champagne Supernova in the Sky

This article is not about the Oasis song but about the discovery of a peculiar supernova. The conventional view is that supernovae of type Ia are the explosion of a white dwarf that has exceeded the so-called Chandrasekar limit. An international team of astronomers led by Canadians has discovered a possible super-Chandra supernova.

The type Ia supernova are of special interest as they are being used as standard candles to measure the expansion of the Universe. Now a team of astronomers led by a group at the University of Toronto has discovered a supernova more massive than previously believed possible. Andy Howell, lead author of the study, identified a Type Ia supernova in a distant galaxy 4 billion light years away that originated from white dwarf whose mass is far larger than any previous example. University of Oklahoma professor David Branch has dubbed this the “Champagne Supernova,” since extreme explosions that offer new insight into the inner workings of supernovae are an obvious cause for celebration.

Friday, September 15, 2006

Star Counts from the Shuttle

Most people have looked up at the dark night sky and have been amazed by the number of stars you can see. What if you were to try that from the Space Shuttle? Canadian astronaut Dr. Steve MacLean will do that during the current shuttle mission.

Dr. McLean had over 600 students do exactly this experiment this summer as part of the Star Count Project organized by NASA and the Canadian Space Agency.

Tuesday, September 05, 2006

Thirty Meter Telescope News

As I've mentioned previously, Canada is a equal (25%) partner in the Thirty Meter Telescope (TMT) Project. The TMT is the world's most ambitious optical telescope project and we can expect the first science images from the telescope in about 2015.

The TMT Project publishes monthly electronic "Newscasts" which cover various aspects of the project. The August issue covers a range of topics including science, technical and management. One article describes how the Project is undergoing a huge cost estimating exercise. The goal is to come up with an accurate cost estimate for the telescope and to have this estimate reviewed by experts later this year.

This issue contains an excellent article by Dr. Tim Davidge of Herzberg Institute of Astrophysics (HIA) in Victoria on studying stars in the Andromeda Galaxy with adaptive optics powered imaging camera on TMT. TMT will have four times the resolution of the Hubble Space telescope and will be able to image stars that are much fainter.

The cover of TIME Magazine declares "How the Stars Were Born" and the accompanying article features TMT Board member Richard Ellis. TMT will greatly enhance our understanding how stars, and galaxies, are born.

This issue of the TMT Newscast includes a Q&A with Dr. David Crampton who is the Instruments Group Leader for TMT and is also the Head of Instrumentation at HIA.


Friday, September 01, 2006

Pluto, 1930 — 2006, RIP

While not necessarily a Canadian story I feel I must make some comments on the planet definition issue. After all, I was one of the IAU members in Prague who actually voted on the four resolutions on the definition of a planet and other Solar System bodies. There are a number of Canadian astronomers who work on Solar System bodies. The Canada France Ecliptic Plane Survey is undertaking a careful survey of Kuiper Belt Objects, of which Pluto is now recognized as the prototype.

The initial Resolution presented to IAU members was seriously flawed. There was wide agreement that something better was needed and this was voiced very vigorously in the Tuesday lunch hour discussion the last part of which is very interesting to watch. The original resolution totally ignored the dynamics of bodies in their definition. After all planets and all other Solar System objects do move!

Personally, I think after the disasterous initial proposal the process to reach the final four Resolutions was much too quick. The IAU should have tabled the issue until the next General Assembly in Rio de Janeiro and set up a more balanced Committee to go back to the drawing board.

I don't think we've heard the last of this and there is a petition of scientists who want to overturn the new IAU definition.

For everyone's information I voted YES, NO, YES, NO on Resolutions 5A, 5B, 6A, 6B.