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.
lol I never noticed he held up three fingers and I was not aware Jackson was back.
"...I was not aware Jackson was back."
I'm Sorry... and I was talking about no spoilers... crap...
Thats ok. I saw a trailer last week that showed him in a robe and I knew he would be making apperances from time to time.
I dont watch it every week. I like mondays and catch up with the old shows. Mcneall does a great job. He is one of my favorite acters.
I also love farscape. Too bad its over.
You must be a scifi fan. I sure wish they would make a movie based on Larry Nivens Ringworld and the Man- Kzin wars.
I am suprised noboby has stepped up and made a fortune onn those. They put Star Wars to shame.
"You must be a scifi fan."
As O'Neill would say, yeahsureyabetcha!
I haven't seen Farscape, though I suppose I'll get around to it. I did just finish up watching the entire Babylon 5 series run, that was great. I was busy with the beginning of my career when season two of B5 started up, and kind of lost track of it after that, so it was great to catch up.
AC-a is a G-type star very similar to ours.. AC-b is a K-1, (early stage orange-yellow star) slightly smaller and cooler than ours.. It is thought that it is sufficient for supporting life, however..
I'm not sure how much interference in "viewing" would be generated by the light of a binary system, but I would guess you are at least partly right as to limits on detecting extra-planetary objects..
Due to the 4 planet Kepler limit, detecting a "jupiter" planet would be a mute point, however.
It couldn't exist..
I checked your link..
The star system referenced is Epsilon Eridanae, and the method used was dust rings..
Present guesses are gas giants anywhere from 5 to 8 times the mass of jupiter in an orbit comparable to that of pluto.. (240 yrs.)
Conclusion:
Not earth type..
You lose..
Just remember that you're standing on a planet that's evolving and revolving at 900 miles an hour,
It's orbiting at 19 miles a second, so it's reckoned, the sun that is the source of all our power.
The Sun and you and me, and all the stars that we can see, are moving at a million miles a day,
In the outer spiral arm, at 40,000 miles an hour, of the Galaxy we call the Milky Way.
Our Galaxy itself contains 100 billion stars, it's 100,000 light-years side-to-side,
It bulges in the middle, 16 000 light-years thick, but out by us it's just 3 000 light-years wide.
We're 30,000 light-years from galactic central point, we go round every 200 million years,
And our galaxy is only one of millions of billions in this amazing and expanding universe.
The universe itself keeps on expanding and expanding, in all of the directions it can whizz,
As fast as it can go, at the speed of light you know, twelve million miles a minute, and that's the fastest speed there is.
So remember, when you're feeling very small and insecure, how amazingly unlikely is your birth,
Pray that there's intelligent life somewhere up in space, because there's bugger all down here on Earth.
And, here's a link to a couple of charts that give some comparitive distances to help wrap your mind around how REALLY BIG the universe is..
WOW!!!! Thank you! Thats what I was looking for. It is mind boggling. 2,200,000 light years to the nearest large galaxy. Light can travel around the earth 7 times in one second? Dam!! Light is FAST!! And it says they are millions of billions of galaxies. I cannot imagine millions of billions. 15 billion light years to the edge of the known universe.
To put that into somewhat of a context it is
one million seconds = 11 years
one billion seconds = 31 years.
One trillion seconds = 318 centuries
I will have to check out the links on that site. I only saw the main page.
Thanks again
Ok, I missed the "earth type" in your original post! Actually, no exo-solar earth type planets are yet known.
1,000,000 seconds/ 3600 sec/hour = 278.8 hours
278.8 hours/24 hours/day = 11.6 days
Opps!! I typed that wrong. You are correct.
heres some more
A billion seconds ago, it was 1972.
A billion minutes ago, Jesus was alive.
A billion hours ago, our ancestors were living in the Stone Age.
A billion dollars ago was only 8 hours and 20 minutes, at the rate Washington spends it.
E=MC(squared)
Where E= expenditures
M= Monetary resources
C= Congress..
Spending other people's money makes it all relative..
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.