| First-ever images of another solar system captured by an international team of astronomers |
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| 13 novembre 2008 | |
Université de Montréal professor and alumni part of nine institutions to make discoveryIn an unprecedented discovery, a team of Canadian, American and British researchers have photographed a distant new planetary system as reported in the November 13 edition of Science Express. The three planets, photographed using Keck and Gemini North telescopes, are young enough to glow at infrared wavelengths resulting from heat generated during their formation.  A luminosity analysis of the three objects, at several infrared wavelengths and different observation periods, reveals that the planets have masses between seven and 10 times that of Jupiter and that they revolve around the central star. The outermost planet travels in an orbit just within a debris disk very similar to the Kuiper Belt of our solar system, where comets originate. This solar system has many similarities with our own. Credits: Gemini Observatory Artwork by Lynette Cook. The mass of the star is about 1.5 times that of the Sun and its age is about 60 million years, significantly below that of the Sun. HR8799 is located 130 light years from the Sun and is barely visible with the naked eye outside major urban centres. A professor from the Department of Physics of the Université de Montréal and two alumni were part of the discovery team: alumnus Christian Marois now of the Herzberg Institute of Astrophysics (Victoria, BC), alumnus David Lafrenière, now of the University of Toronto, and professor René Doyon, director of the Mont-Mégantic Observatory and member of the Centre de Recherche en Astrophysique du Québec (CRAQ). Christian Marois says this is the first time that a scientific team secured images of several planets around a star outside our solar system. He adds the discovery is a crucial step towards finding a planet resembling Earth: “All major telescopes around the world will now be pointed towards this star to learn more about this fascinating new solar system.” said co-author René Doyon. A previous survey – the GPDS (Gemini Deep Planet Survey) – on the Gemini North telescope, codirected by René Doyon and David Lafrenière between 2004 and 2007, showed that giant planets such as Jupiter are relatively rare around young stars with orbital separations on the scale of our solar system. “Using the ADI technique, we searched around 85 young stars of mass no greater than the Sun, and no planets were found. The next step was to search around a larger number of stars and especially those more massive than the Sun. This system is a gift from Nature. It’s incredible that our first detection found not one, not two, but three planets around the same star,” says Doyon.  Figure 1 – Left: star HR8799 photographed by the Keck telescope. Right: the same star after ADI image processing. The three planets appear distinctly as red dots at 1h, 5h and 10h approximately. The three planets revolve counterclockwise at orbital distances of 25, 40 and 70 astronomical units (AU). One astronomical unit is the mean distance between the Earth and the Sun. Credits: Gemini Observatory Artwork by Lynette Cook.  Figure 2 - Left: Schematic representation of planetary system HR879 (left) compared on the same scale with our solar system. The members of the discovery team are: Christian Marois – NRC Herzberg Institute of Astrophysics, Victoria, BC Bruce Macintosh – Lawrence Livermore National Laboratory, Livermore, CA, USA Travis Barman – Lowell Observatory, Flagstaff, AZ, USA Benjamin Zuckerman – Astronomy Dep’t, University of California, Los Angeles, CA, USA Jennifer Patience – School of Physics, University of Exeter, Exeter, UK Inseok Song – University of Georgia, Athens, GA, USA David Lafrenière – Dep’t of Astronomy and Astrophysics, University of Toronto, Toronto, ON René Doyon, Department of Physics, Université de Montréal, CRAQ, Montréal, Qc Media contacts: Olivier Hernandez, Ph. D. Media relations, CRAQ – Université de Montréal Telephone: 514-343-6111, ext. 4681 Cell.: 514-582-9802 Email: olivier@astro.umontreal.ca Sylvain-Jacques Desjardins |
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