Telescopes see 'distant planet'
BBC News | April 4, 2005
A European team claims to have obtained the first direct image of a planet beyond our own Solar System.
The "extrasolar planet" is said to orbit a star called GQ Lup - thought to be like a young version of our Sun.
Similar claims have been made in the past, but sceptical scientists believe the pictures merely show objects that share the same view in the sky.
The GQ Lup object is far more certain claims Ralph Neuhaeuser's team in the journal Astronomy & Astrophysics.
GQ Lup and its companion are located in a star-forming region about 400 light-years away.
The "planet" has been observed by the team since 1999.
The astronomers have used image data from the European Southern Observatory's (ESO) Very Large Telescope (VLT) in Chile, the Hubble Space Telescope and the Japanese Subaru Telescope in Hawaii.
Because it is in a young system, the planet is said to be relatively hot. This helped the team detect the planet in the glare from its host star, the group says.
The planet is also quite far from GQ Lup - about 100 times the distance between the Sun and the Earth, which assisted the team in separating the light from the two objects.
The team models the mass of the companion to be 1-2 times that of our own Jupiter.
Astronomers have found about 130 exoplanets over the past decade, but most of these have been detected via the gravitational "wobbles" they induce in their parent stars.
The limitations of current technology make it very difficult to see a planet directly.
It is expected that such images will not become routinely available until new space-borne planet-hunting telescopes are launched in the next decade.
Some scientists have already questioned whether the GQ Lup companion is an exoplanet. Professor Mark McCaughrean, from Exeter University, UK, said he had concerns over the mass of the object, which by the team's own admission could be as high as 42 Jupiters.
"Almost all current theoretical models would peg the mass of this object at somewhere between 15 and 40 Jupiters: it's much more likely to be a brown dwarf (a failed star), not a planet", he said.
Professor McCaughrean added that while it appeared to be moving across the sky with the same velocity as GQ Lup, the companion could be just another faint object in the same region as the star, without being bound to it by gravity.
"There is no evidence whatsoever for true orbital motion of the faint source round the bright one," the Exeter researcher told the BBC News website.