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.
Yes, I am aware that such does not exist..
Yet, I am confident that given the proper impetus, ( like discovery of an earth like planet close by ) that someone would figure out a way to get us there quickly.. ( if not safely..)
As the article made clear, the stars in these systems are too bright to image any planets that might be there.
Most of the extrasolar planets that have been found are of an extremely odd type: hugely massive planets in wildly elliptical, short-period orbits that pass extremely close to their stars. Not every star has planets like these. Ours doesn't. If we lived on Alpha Centauri, I doubt we'd be able to detect Jupiter, let alone Earth, with the tools we have now.
Maybe you should break the news to the folks at NASA...
There's no reason to believe it's possible. In fact, I'll go on record here and say it's impossible. If some experimental fact should demonstrate to me that I'm wrong, I'll happily print this post out on coarse paper, and eat it.
If we lived on Alpha Centauri, I'd bet we'd be pretty darn hot! =)
She came from planet Clair
She came from there
She drove a Plymouth Satellite
Faster than the speed of light...
I always thought planet Clair would be pink (magenta).
Oddly enough, that's what I say about relativity. ;^)
Alpha Cent is a double star. Might not be any planets except very far out.
;)
< in a lisp > A pinkth sthate! Fabulous!
< /barney frank >
Actually, using a few calculations on the effects of gravity, it has been determined that either star of Alpha Cen would be able to hold a planet individually as far out as Mars' distance from the sun. So, theoretically there could be a liveable planet there around either. Alpha Cen A is like the sun, but a bit larger, and Alpha Cen B a bit cooler and smaller, but both within the range that could support a life bearing planet, in theory.
I'll take your bet. Here's your planets:
http://cfa-www.harvard.edu/planets/eps-Eri.html
Done and done. Where do I send the check?
(This reminds me of the classic sci-fi short story "The Marching Morons.") "Suuuuuure we'll send you to the pink planet."
I have asked this before but I love seeing the "scale" of the universe. Does anyone know a good website that starts with our solar system and expands outward?
Sort of like the basketball court where the sun is at one end about the size of a basketball, then Mercury like a pea moving to Jupiter the size of a softball.
I have done some google but cant find a good one that shows the galaxys and the universe on a smaller scale. Maybe some easy to understand info on how far the next galaxy is from us.
I am like Col. Mcneill compared to Samatha on stargate
"I am like Col. Mcneill compared to Samatha on stargate."
O'Neall!! Not "Mc"Neall! Sheesh...
;)
Would a planet near either A or B possibly have a circular orbit? Seems like our powerful new adaptive telescopes would be able to resolve such a planet.
The system would only have small Earth-like planets, not giants like Jupiter as they would have been too far out to develop. We can only detect planets Jupiter's size or larger.
At least I remembered TWO L's!!!!!!!!!!!
For some reason I really like that show. I loved the movie and the TV show isnt getting old. It seems to just get better. Same with Stargate Atlantis.
(Two L's, three fingers... gotta love it...)
I feel the same about the show, though I have to keep up on broadcast channels. Daniel's only just come back for me, so no spoilers, please.
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