Skip to comments.Scientists Say Red Speck Is Indeed Huge New Planet
Posted on 04/29/2005 10:22:03 PM PDT by neverdem
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 Neuhäuser 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.
In a second paper, to appear in the same journal, Dr. Chauvin's team is reporting another discovery, of a companion to the star AB Pictoris, a young star about 150 light years from Earth. That object, known as AB Pic b, is about 13 or 14 times the mass of Jupiter, they estimate, putting it right on the line between planets and brown dwarfs.
Like the earlier planet and GQ Lup, AB Pic b is orbiting at an enormous distance from its star, 23 billion miles, and that is a new puzzle for the planet hunters, Dr. Ben Zuckerman of the University of California, Los Angeles, a member of the team, said. Dr. Zuckerman noted that these were very far out compared with any previously known planets, which raised questions about how and where they had formed.
"It's a new kind of system," Dr. Zuckerman said, adding that they are also rare. "They are relatively few and far between."
FReepmail me if you want on or off my health and science ping list.
Put that in MapQuest! That's far, far away
Caption to image in #5
Caption: ESO PR Photo 14a/05 The first planet outside of our solar system to be imaged orbits a brown dwarf (centre-right) at a distance that is nearly twice as far as Neptune is from the sun. The photo is based on three near-infrared exposures (in the H, K and L' wavebands) with the NACO adaptive-optics facility at the 8.2-m VLT Yepun telescope at the ESO Paranal Observatory.
Thanks for the pic. Where did you happen to find it?
You'll know if it's a real planet if there's ReMax 'For Sale' signs all over it.
Thats 23 billion miles from the parent star.
The planet is about 1,350 trillion miles away from us.
What do you think of that?
Liberties. You would have to stack on about 79 more Jupiters to ignite it into a "brown dwarf"
I don't mean necessarily into a brown dwarf, I mean any kind of star. Are you saying it would take a mass of 79 jupiters to start fusing hydrogen?
As an addendum, when it was written, it was generally thought Jupiter was at the near-limit.
As more science was gathered on Jupiter and theories developed, it was later established that Jupiter was in fact, far too small.
This was confirmed through the discoveries of extrasolar planets starting in 1990 having masses of 20-50 Jupiters.
(Note, these planets were all discovered indirectly through "wobble" and "occultation" observations, never directly)
Well, about 80 Jupiters is thought to be the flashpoint.
And even then it would be a very dull star. "Brown dwarf"