Posted on 01/12/2005 7:07:27 AM PST by Momaw Nadon
Astronomers have directly observed an extrasolar planet for the first time, but are at a loss to explain what they see.
More than 130 planets have been detected orbiting stars other than our own, the Sun. But because the stars far outshine the planets, all of the planets were detected indirectly - by how much they made their host stars wobble or dim, for example.
Now, astronomers say they are almost certain they have snapped an actual image of an extrasolar planet. It was first seen at infrared wavelengths with the Very Large Telescope in Chile in April 2004, and announced at the American Astronomical Society annual meeting in San Diego, California, US on Monday. It appeared alongside a brown dwarf - an astronomical object with a mass inbetween that of a planet and a star.
But astronomers could not immediately confirm that the planet was gravitationally linked to the brown dwarf. So in August 2004, researchers used the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer to observe the pair again. And they found them in the same relative positions, as would be expected for objects in an estimated 2500-year orbit.
Spectral signature
If the finding is borne out by further Hubble observations in April 2005, the images could also reveal information about any atmosphere the planet might have, says team member Glenn Schneider of the University of Arizona, US. Dust clouds, for example, could absorb certain wavelengths of light and leave behind a particular spectral signature, he says.
Several factors helped make the find possible. The fact that the planet - which is five times as massive as Jupiter - orbits a brown dwarf made it stand out more easily. Brown dwarfs, unlike stars, do not burn hydrogen and are therefore relatively dim.
It also lies about 7.5 billion kilometres away from the brown dwarf, which is called 2MASSWJ 1207334-393254 ("1207" for short). That distance - about a third farther than Pluto is from our Sun - helped astronomers visually distinguish the two objects.
Flung outward
But the great distance also puzzles the team, as planets in most solar systems, including our own, tend to lie much nearer their host stars. "They may have formed closer in and [the planet] migrated outward," says team member Eric Becklin, an astronomer at the University of California in Los Angeles, US.
Indeed, simulations suggest pairs of planets about the size of Jupiter can interact as solar systems take shape, with the more massive one being flung outward and the smaller one being hurled toward the star. But it remains possible that "planets may be forming out there" at surprisingly large distances, says Schneider.
Astronomers do not know whether brown dwarfs form in a similar way to stars - though much less spectacularly - or like planets out of a dusty disc. But Hubble observations hint that this brown dwarf may have formed like a star, in a group of young stars about 8 million years old.
The team has been observing 116 nearby stars and brown dwarfs with Hubble since July 2004. So far, they have seen three other candidate planets, all around conventional stars. Follow-up observations with Hubble will confirm whether these are real planets or background objects.
My home planet!
The pink spot is planet Liberal.
Great, another place they can go to after the election.
We can call it the "pink state"
Though, it is a little farther away then France or Canada. They will probably ask us to pay for the trip.
I think my ex-girlfriend hails from there.
I'd be willing to chip in for their expenses.
"...and all the tree's are red...."
"...They will probably ask us to pay for the trip..."
Well worth the expense, Don't you think???
The circled area indicates where the "parent" star would be. It has been obscured so that the planet shows up better.
Pictures and stories about deep space fascinate me. I miss Petuniavision and her daily displays and articles. Please come back.
so your saying the tiny pink dot outside the circle is the planet?
There are approx. 34 star systems within 23 light years of our "Sol(ar) system...
Yet, we haven't determined if there are planets in any of those systems?
Alpha Centauri, / Beta Centauri, only 4.5 LY from earth..
Barnard's Star, something like 6 LY..
Epsilon Eridani, Sirius, Wolf(356?)....
Sometimes these astronomers don't seem to be able to see the forest for the trees...
Show us an earth-type planet within 10 LY of earth, and we'll have ships with warp drive within a decade..
Just tell em Hale Bopp will be back shortly and they can get aboard the mother ship then.
You do realize that "warp drive" is not a technological concept but merely the figment of Gene Roddenbury's wife's mind, right?
right. The article also says this, see the caption under the picture.
Star Trek mumbo jumbo tech talk is fun. My all time favorite is alluvial dampers. I imagine the warp engines oozing silt and dirt when things go wrong.
http://en.wikipedia.org/wiki/Alcubierre_drive
Some very dilligent physicists are working on FTL issues. It isn't impossible, merely exotic.
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