NATURE, the scientific journal, will publish on the 26 January 2006, a major paper on a discovery addressing extra-solar planets. The European Southern Observatory ESO contributed to this publication and has produced a Video News Release featuring new 3-D graphics, background footage and interviews.
On 25 January at 17:30 GMT, the script for this TV Exchange will be posted as a PDF file under http://television.esa.int/photos/EbS44312.pdf A pre-view video clip will be online on the ESA TV Website as of that time.
Title: The possibility of detecting planets in the Andromeda Galaxy Authors: S.-J. Chung (1), D. Kim (1) The Angstrom Collaboration: M.J. Darnley (2), J.P. Duke (2), A. Gould (4), C. Han (1), Y.-B. Jeon (3), E. Kerins (2), A. Newsam (2), B.-G. Park (3) ((1) Chungbuk Natl. Univ., Korea, (2) Liverpool John Moores University, (3)Korea Astronomy and Space Science Institute, (4) OSU)
The Angstrom Project is using a global network of 2m-class telescopes to conduct a high cadence pixel microlensing survey of the bulge of the Andromeda Galaxy (M31), with the primary aim of constraining its underlying bulge mass distribution and stellar mass function. Researchers investigate the feasibility of using such a survey to detect planets in M31. They estimate the efficiency of detecting signals for events induced by planetary systems as a function of planet/star mass ratio and separation, source type and background M31 surface brightness., and find that for planets of a Jupiter-mass or above that are within the lensing zone (~1 -3 AU) detection is possible above 3 σ, with detection efficiencies ~3% for events associated with giant stars, which are the typical source stars of pixel-lensing surveys. A dramatic improvement in the efficiency of ~40 - 60% is expected if follow-up observations on an 8m telescope are made possible by a real-time alert system.
It's the faint red object, not the bright white one that might be a historic find.
The white object is surely a brown dwarf star.
Quite possibly, however, the red object is the first direct image of a planet beyond our Solar System. The intriguing possibility was first reported last year, but many astronomers weren't then convinced that the "planet" was not just a background star.
Earlier this year, the 2M1207 star system was imaged twice more in an effort to resolve the issue. To the delight of the scientific team, the objects kept the same separation, indicating that they are gravitationally bound. The faint red object 2M1207b is therefore 100 times fainter, intrinsically, than the bright white brown dwarf 2M1207b -- a characteristic well explained by a planet roughly five times the mass of Jupiter.
The discovery - still subject to further conformation - is considered a step toward the more ambitious goal of imaging Earth-like planets orbiting distant stars. The image was taken with the high-resolution adaptive-optic NaCo camera attached to the 8-meter Very Large Telescope Yepun in Chile.
"This is the first time we have actually seen light." The planets, HD 209458b and TrES-1, as observed from Earth, take them behind their host stars. Astronomers took advantage of this alignment, to extract the planets' radiation from infrared images captured by NASA's Spitzer space telescope. The planet, HD 209458b, has a mass two-thirds that of Jupiter and surface temperatures of 700°C, orbits a sun-like star in the constellation of Pegasus about 140 light years from Earth.
Ten years after finding the first planet outside our solar system, scientists say they may be ready to move into a new phase of planetary exploration -- one that examines distant worlds for signs of Earth-like life.
So far, astronomers have discovered some 145 so-called extrasolar planets orbiting stars besides our sun. All are gas giants like Jupiter, thought to be inhospitable to life as it is known on Earth. But some of the world's premier planet hunters indicated this could change in the next decade. "Within a few years, we may be able to detect things like our own solar system." - Mario Livio, an astrophysicist at the Space Telescope Science Institute. That could help answer what he termed the most intriguing question in science today: is there intelligent life anywhere besides Earth? "The capability of seeing, detecting, planets the size of the Earth is only now just coming into our grasp." - Jaymie Matthews, an astronomer at the University of British Columbia. "I think we can look forward reasonably in the next decade to finding out are there Earth-size planets in Earth-like orbits going around every star. We're going to have to wait a while to find out whether they have atmospheres." - Tim Brown of the National Centre for Atmospheric Research. Matthews, Livio and Brown were among scientists gathered last week (May 1st 2005) for a symposium on a decade of research into extrasolar planets at the Space Telescope Science Institute in Baltimore, which deals with data gathered by the Hubble Space Telescope.
Since the first extrasolar planet was detected in 1995 around a star known as 51 Pegasi, astronomers have uncovered dozens by identifying stars that wobble because of the gravitational pull of planets around them. They have found others by watching for a very slight dimming of stars caused by the orbiting of planets. Getting even a blurry image of an extrasolar planet has proven tricky. The closest astronomers have come is a picture of a fuzzy-looking red ball orbiting a brown dwarf 200 light-years from Earth. A light-year is about 6 trillion miles, the distance light travels in a year.
Some astronomers said in April the image was a confirmed extrasolar planet; others disagree. If it is a planet, it is no place for humans, at five times Jupiter's size and waltzing closely around the brown dwarf, a kind of failed star. Michel Mayor of Switzerland's Geneva Observatory, a discoverer of the first-known extrasolar planet, expects most normal stars to have the potential for planetary systems. "I think it would be amazing to say that they're not around many stars, but to say that they're around every star would be I think pushing it," - Michel Mayor. More planet discoveries would mean a larger data base, which would help determine the best conditions for planet formation. Technology is also expected to develop that would allow detection of ever-smaller planets, to the size of Earth. Already some astronomers have moved from seeking extrasolar planets to exploring those already found. These include Matthews, who works with the Canadian spacecraft known as MOST -- short for Micro variability and Oscillations in Stars. A tiny orbiting "suitcase in space," MOST watches stars with extrasolar planets to see how they dim as their planets pass. It can also monitor the reflected light from big Jupiter-type planets circling close to their stars.