Astronomers Take 1st Picture of Planet Outside Solar System
European and American astronomers have taken the first pictures of a planet five times the size of Jupiter that is orbiting a star in a different solar system. The international team of scientists discovered the object last year as a red speck of light circling a brown star. Astronomers estimate the extra-solar planet is 225-light years away from Earth in the Hydra constellation.
Since the mid-1990s, scientists have discovered more than 100 of these objects, though imaging them directly has been difficult. But images of the recently discovered giant planet and dwarf star were captured early this year by the Very Large Telescope (Interferometer at the European Southern Observatory’s Paranal Observatory) in northern Chile.
Scientists say the planet – called 2M1207b – it is the first planet ever imaged outside of the Earth’s solar system.
Interesting. I would recommend a name change, however. “2M1207b” sounds more like a password than a planet.
The NYT coverage has more background information.
A reddish speck photographed near a dim and distant star last year is indeed a planet, about five times the mass of Jupiter, an international team of astronomers is reporting today. They say the results bolster their claim, put forward last fall, that this image was the first of a planet orbiting a star outside the solar system. The planet, about 230 light-years from Earth in the constellation Hydra, orbits a kind of failed star known as a brown dwarf at a distance of at least five billion miles, twice as far as icy Neptune is from our own Sun. Spectroscopic measurements show water vapor in its atmosphere, suggesting that it is cold like a planet and not hot like a star.
“This discovery offers new perspectives for our understanding of chemical and physical properties of planetary mass objects as well as their mechanisms of formation,” Dr. Gael Chauvin of the European Southern Observatory in Chile and his colleagues wrote in the paper, in the journal Astronomy and Astrophysics.
When Dr. Chauvin’s group first announced the discovery of the object, known officially as 2M1207b, last year, they admitted that they could not prove that it was not just a background object unrelated to the brown dwarf. Subsequent observations using the Very Large Telescope on Cerro Paranal in northern Chile and a system designed to take the twinkle out of starlight and thus get sharper images showed that the dwarf star and the suspected planet were moving together across the sky, cementing the notion that they are gravitationally bound. Measurements of the same system with the Hubble Space Telescope are to be reported on Monday in Baltimore at a meeting on extrasolar planets.
In the last decade, astronomers have detected, by indirect means, some 150 planets around other stars, setting off a race to see these objects in their own light. Such observations will allow them to study the composition and other properties of these “exoplanets” and compare them to the denizens of the solar system and to one other.
In the year it has taken the European group to cement its claim, other groups have claimed to have seen the first light from extrasolar planets. Last month, for example, a group led by Dr. Ralph NeuhÃƒ¤user of Jena University in Germany, using the same telescope and camera, reported that they had imaged a planet of two Jupiter masses circling the star GQ Lup. But some astronomers have questioned the reliability of their estimate of its mass, arguing that it could be heavy enough to be a brown dwarf.
Update: Photo added above by popular request. Not much of a photo to my untrained eyes, frankly.