Wednesday, May 5, 2010
Hubble's Universe: Extrasolar Planets
Hubble's Universe Unfiltered (Episode 7): Eye Spy A Planet (Part 2/2) - Extrasolar Planets.
Up until the 1990s, we only knew of the planets in our own solar system. Since then, we have discovered over 300 planets orbiting other stars (extrasolar planets, exoplanets). However, most of these planets were found when scientists observed the effect of the planet's gravity upon their host stars.
Astronomers could not show the world what we wanted most: a visible light picture of a planet around a star like the Sun. That situation changed in November 2008 with a discovery by the Hubble Space Telescope. Join us for the story that begins a new era in our knowledge of planetary systems.
Hubble press release:
Hubble Directly Observes Planet Orbiting Fomalhaut
http://hubblesite.org/newscenter/arch...
---
Notes
- Note that Hubble's discovery of Fomalhaut b is billed as the "first visible-light snapshot of a planet orbiting another star." It is important to note that the first direct detection of a planet will likely turn out to be the planet known as 2M1207 b. However, the host, 2M1207, is not a full-fledged star, but a brown dwarf (see below). In addition, pictures of three planets around HR 8799, released the same day as the Fomalhaut discovery, were taken in the infrared.
- Let me clarify about 2M1207. It has less than 3% the mass of our Sun, roughly 25 times the mass of Jupiter. That mass places it in the brown dwarf category: large enough to ignite deuterium fusion in its core (thus not a planet), but not large enough for hydrogen fusion (thus not a star). Brown dwarfs glow faintly at formation and then spend the rest of their lives cooling and fading away. Brown dwarfs are generally thought to be those objects with between 15 and 70 times the mass of Jupiter.
- I wanted to make a joke that what the Hubble image of Fomalhaut looked most like is the "Eye of Sauron" from the "Lord of the Rings" movies. However, New Line Cinema did not respond to my requests for permission, and my producer would not let me use the image in the podcast. That joke is one reason why the episode is called "Eye Spy."
- A betting astronomer might have chosen Beta Pictoris as the first star around which a planet would have been seen. We have been getting intriguing evidence that planets should be there for more than a decade. However, since the disk in the Beta Pic system is roughly perpendicular to our line of sight, any planets will travel in front of and behind the star from our point of view. Hence, we could only observe them well during parts of their orbits. Face-on systems, like HR 8799, are much more favorable for direct images.
- If confirmed, the Beta Pictoris planet would indicate that giant planets can form quickly. Beta Pictoris is about 12 million years old. We believe that giant planets must form within the first 10 or so million years of a developing system, as winds and radiation from newborn stars should remove the gas from the system on that timescale. A giant planet needs to accrete some of that gas during its formation, and thus must form in millions of years. In contrast, it is thought that Earth may take as much as a couple hundred million years to form.
• http://hubblesite.org/
---
Hubble's Universe Unfiltered is a collection of video podcasts. Each episode offers an in-depth explanation of the latest news story or image from the Hubble Space Telescope, presented by astronomer Frank Summers.
• http://hubblesite.org/explore_astrono...
Tuesday, May 4, 2010
LHC Sets Collision Record - New Era For Particle Physics
CERN News: The Large Hadron Collider (LHC) sets collision record - new era in the history of particle physics.
Spotlight on CERN - LHC First Physics -- On March 30th 2010, first high-energy collisions took place at 7 TeV in the LHC, creating a phenomenal quantity of data. This not only marked the start of a new era for particle physics but also presents an enormous challenge in the field of computing, in terms of data transfer, storage and processing.
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle accelerator, a synchrotron intended to collide opposing particle beams of either protons at an energy of 7 trillion electronvolts (1.12 microjoules) per particle, or lead nuclei at an energy of 574 TeV (92.0 µJ) per nucleus. The term hadron refers to particles composed of quarks. It is expected that it will address the most fundamental questions of physics, advancing our understanding of the deepest laws of nature. The LHC lies in a tunnel 27 kilometres (17 mi) in circumference, as much as 175 metres (574 ft) beneath the Franco-Swiss border near Geneva, Switzerland.
The Large Hadron Collider was built by the European Organization for Nuclear Research (CERN) with the intention of testing various predictions of high-energy physics, including the existence of the hypothesized Higgs boson and of the large family of new particles predicted by supersymmetry. It is funded by and built in collaboration with over 10,000 scientists and engineers from over 100 countries as well as hundreds of universities and laboratories.
• http://en.wikipedia.org/wiki/Large_Ha...
• http://lhc.web.cern.ch/
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Sunday, May 2, 2010
Looking To The End Of Time
Hubble Space Telescope - 15 Years of Discovery (Episode 9): Looking To The End Of Time - The Hubble Ultra Deep Field.
The NASA/ESA Hubble Space Telescope is one of the biggest scientific projects of all time and is approaching the 15th anniversary of its launch.
In many ways Hubble is the most successful scientific project in the World, and this event is not likely to go unnoticed. The European Space Agency, ESA, has decided to celebrate this anniversary with the production of a Hubble 15th Anniversary movie called "Hubble - 15 Years Of Discovery".
The movie covers all aspects of the Hubble Space Telescope project: a journey through the history, the trouble and the scientific successes of Hubble.
This portrait of one of the biggest scientific projects of all time contains large amounts of previously unpublished footage in uncompromised quality.
With the beautiful backdrop of Hubbles visual image treasures running as a red line through the movie, the light and dreaming style tells the most interesting stories about our fascinating Universe and about the change of vision that Hubble has brought us.
---
The Hubble Space Telescope (HST), named after Edwin Powell Hubble (1889-1953) who was one of the great pioneers of modern astronomy, is a collaboration between ESA and NASA. It is a long-term, space-based observatory. The observations are carried out in visible, infrared and ultraviolet light.
In many ways Hubble has revolutionised modern astronomy, not only by being an efficient tool for making new discoveries, but also by driving astronomical research in general.
During 15 years of viewing the sky, Hubble has taken more than 700000 exposures of more than 22 000 celestial objects. The spacecraft itself has whirled around Earth nearly 88 000 times, travelling more than 4000 million kilometres.
The orbiting observatory generates enough data every day - about 15 gigabytes - to fill more than three DVDs, and in total it has produced 23 terabytes of data, equal to the amount of text in 23 million novels.
Over 3900 astronomers from all over the world have used the telescope, and compiled a long list of scientific achievements, published in more than 4000 papers, such as:
- calculating the precise age of the Universe to be 13 700 million years old);
- confirming the existence of a strange form of energy called dark energy;
- detecting small proto-galaxies that emitted their light when the Universe was less than a 1000 million years old;
- proving the existence of super-massive black holes;
- seeing a comet hitting Jupiter; and
- showing that the process of forming planetary systems is common throughout the galaxy.
• http://www.esa.int
• http://www.spacetelescope.org
Friday, April 30, 2010
Eye Spy A Planet: Our Solar System
Hubble's Universe Unfiltered (Episode 7): Eye Spy A Planet (Part 1/2) - Our Solar System.
Up until the 1990s, we only knew of the planets in our own solar system. Since then, we have discovered over 300 planets orbiting other stars (extrasolar planets, exoplanets). However, most of these planets were found when scientists observed the effect of the planet's gravity upon their host stars.
Astronomers could not show the world what we wanted most: a visible light picture of a planet around a star like the Sun. That situation changed in November 2008 with a discovery by the Hubble Space Telescope. Join us for the story that begins a new era in our knowledge of planetary systems.
Hubble press release:
Hubble Directly Observes Planet Orbiting Fomalhaut
http://hubblesite.org/newscenter/arch...
---
Notes
- Note that Hubble's discovery of Fomalhaut b is billed as the "first visible-light snapshot of a planet orbiting another star." It is important to note that the first direct detection of a planet will likely turn out to be the planet known as 2M1207 b. However, the host, 2M1207, is not a full-fledged star, but a brown dwarf (see below). In addition, pictures of three planets around HR 8799, released the same day as the Fomalhaut discovery, were taken in the infrared.
- Let me clarify about 2M1207. It has less than 3% the mass of our Sun, roughly 25 times the mass of Jupiter. That mass places it in the brown dwarf category: large enough to ignite deuterium fusion in its core (thus not a planet), but not large enough for hydrogen fusion (thus not a star). Brown dwarfs glow faintly at formation and then spend the rest of their lives cooling and fading away. Brown dwarfs are generally thought to be those objects with between 15 and 70 times the mass of Jupiter.
- I wanted to make a joke that what the Hubble image of Fomalhaut looked most like is the "Eye of Sauron" from the "Lord of the Rings" movies. However, New Line Cinema did not respond to my requests for permission, and my producer would not let me use the image in the podcast. That joke is one reason why the episode is called "Eye Spy."
- A betting astronomer might have chosen Beta Pictoris as the first star around which a planet would have been seen. We have been getting intriguing evidence that planets should be there for more than a decade. However, since the disk in the Beta Pic system is roughly perpendicular to our line of sight, any planets will travel in front of and behind the star from our point of view. Hence, we could only observe them well during parts of their orbits. Face-on systems, like HR 8799, are much more favorable for direct images.
- If confirmed, the Beta Pictoris planet would indicate that giant planets can form quickly. Beta Pictoris is about 12 million years old. We believe that giant planets must form within the first 10 or so million years of a developing system, as winds and radiation from newborn stars should remove the gas from the system on that timescale. A giant planet needs to accrete some of that gas during its formation, and thus must form in millions of years. In contrast, it is thought that Earth may take as much as a couple hundred million years to form.
• http://hubblesite.org/
---
Hubble's Universe Unfiltered is a collection of video podcasts. Each episode offers an in-depth explanation of the latest news story or image from the Hubble Space Telescope, presented by astronomer Frank Summers.
• http://hubblesite.org/explore_astrono...
Thursday, April 29, 2010
Hubble 20 Years of Space-Shattering Discoveries
NASA's tribute to the Hubble Space Telescope on its 20th anniversary in space. This beautiful video surveys the incredible accomplishments of this revolutionary instrument: everybody's favorite telescope.
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