Skip to comments.Rapid-born planets present 'baby picture' of our early solar system
Posted on 09/09/2005 9:39:51 PM PDT by DaveLoneRanger
Using NASA's Spitzer Space Telescope, a team of astronomers led by the University of Rochester has detected gaps ringing the dusty disks around two very young stars, which suggests that gas-giant planets have formed there. A year ago, these same researchers found evidence of the first "baby planet" around a young star, challenging most astrophysicists's models of giant-planet formation.
The new findings in the Sept. 10 issue of Astrophysical Journal Letters not only reinforce the idea that giant planets like Jupiter form much faster than scientists have traditionally expected, but one of the gas-enshrouded stars, called GM Aurigae, is analogous to our own solar system. At a mere 1 million years of age, the star gives a unique window into how our own world may have come into being.
"GM Aurigae is essentially a much younger version of our Sun, and the gap in its disk is about the same size as the space occupied by our own giant planets," says Dan Watson, professor of physics and astronomy at the University of Rochester and leader of the Spitzer IRS Disks research team. "Looking at it is like looking at baby pictures of our Sun and outer solar system," he says.
"The results pose a challenge to existing theories of giant-planet formation, especially those in which planets build up gradually over millions of years," says Nuria Calvet, professor of astronomy at the University of Michigan and lead author of the paper. "Studies like this one will ultimately help us better understand how our outer planets, as well as others in the universe, form."
The new "baby planets" live within the clearings they have scoured out in the disks around the stars DM Tauri and GM Aurigae, 420 light years away in the Taurus constellation. These disks have been suspected for several years to have central holes that might be due to planet formation. The new spectra, however, leave no doubt: The gaps are so empty and sharp-edged that planetary formation is by far the most reasonable explanation for their appearance.
The new planets cannot yet be seen directly, but Spitzer's Infrared Spectrograph (IRS) instrument clearly showed that an area of dust surrounding certain stars was missing, strongly suggesting the presence of a planet around each. The dust in a protoplanetary disk is hotter in the center near the star, and so radiates most of its light at shorter wavelengths than the cooler outer reaches of the disk. The IRS Disks team found that there was an abrupt deficit of light radiating at all short infrared wavelengths, strongly suggesting that the central part of the disk was absent. These stars are very young by stellar standards, about a million years old, still surrounded by their embryonic gas disks. The only viable explanation for the absence of gas that could occur during the short lifetime of the star is that a planet--most likely a gas giant like our Jupiter--is orbiting the star and gravitationally "sweeping out" the gas within that distance of the star.
As with last year's young-planet findings, these observations represent a challenge to all existing theories of giant-planet formation, especially those of the "core-accretion" models in which such planets are built up by accretion of smaller bodies, which require much more time to build a giant planet than the age of these systems.
The IRS Disks team discovered something else curious about GM Aurigae. Instead of a simple central clearing of the dust disk, as in the other cases studied, GM Aurigae has a clear gap in its disk that separates a dense, dusty outer disk from a tenuous inner one. This could be either an intermediate stage as the new planet clears out the dust surrounding it and leading to a complete central clearing like the other "baby planet" disks, or it could be the result of multiple planets forming within a short time and sweeping out the dust in a more complex fashion.
GM Aurigae has 1.05 times the mass of our Sun-a near twin--so it will develop into a star very similar to the Sun. If it were overlaid onto our own Solar System, the discovered gap would extend roughly from the orbit of Jupiter (460 million miles) to the orbit of Uranus (1.7 billion miles). This is the same range in which the gas-giant planets in our own system appear. Small non-gas-giant planets, rocky worlds like Earth, would not sweep up as much material, and so would not be detectable from an absence of dust.
The Spitzer Space Telescope was launched into orbit on Aug. 25, 2003. The IRS Disks research team is led by members that built Spitzer's Infrared Spectrograph, and includes astronomers at the University of Rochester, Cornell University, the University of Michigan, the Autonomous National University of Mexico, the University of Virginia, Ithaca College, the University of Arizona, and UCLA. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology, also in Pasadena.
"The results pose a challenge to existing theories of giant-planet formation, especially those in which planets build up gradually over millions of years"
This is not so much evidence in favor of Biblical creation, because the Bible says that God created the sun, stars and planets on day 4. However, scientists insist that the earth and other planets are billions of years in the making...turns out they were wrong again. It is evidence against evolution as an explanation for origins.
What scientists claim this?
The Earth is about 4.6 billion years old. However, it did not take billions of years to form.
How 'long' DID it take?
They were never actually wrong, you see, it's just now they are more right. How could you ever think they were wrong? They have mutated in to error-free creatures.
Evolution and planetary formation are two entirely different animals. I get extremely annoyed when creationists try to lump them together.
I'm talking on a more general scale, Froggo. I recognize that planetary formation is not connected with the alleged biological evolution that you believe took place to form complex life forms from primordial goo. The point of this article is, planets formed "faster than we thought." We're suddenly finding out, all these processes don't take as long as evolutionists have said they do. Planetary formation being the latest one.
Planetary cosmologists are not evolutionists.
For one thing, you don't see them going on a rant against people who say planetary formation is faster than expected. You don't see them denying evidence that weakens or undermines a theory.
In short, you don't see them acting the way evolutionists do when faced with contradictory evidence, so to compare the two is nothing more than propaganda to promote an agenda.
Finally, since evolution doesn't start until AFTER the plnaets have formed and stabilized, how long planet formation took is totally irrelevant to the issue of evolution.
Oh, and just as a point of order, it might be prudent in the future to ask what someone believes instead of just assuming, because you look really foolish when you assume wrong.
They are talking about only a single process, formation of gas giant planets. This in no way contradicts the age of the solar system, stellar formation, galactic formation, the big bang, evolution or, in that matter, any evidence pointing to either the age of the solar system or the age of the universe.
billions of years in the making
You need to read the article more carefully. From the article: "especially those in which planets build up gradually over millions of years". That is a far cry from "billions".
Here are some interesting links on this:
The following link is really interesting and from 2000:
And finally, here ya go:
Earth is about 4.6 billion years old, the speed with which it formed (which this article doesn't comment on, since the Earth is terrestrial and not gaseous) has little to do with its age.
This one didn't work.
It didn't work last night. I even cut and pasted it into the address box.
Now this morning it works!
51 Pegasi Planetary System
"51 Pegasi b has the distinction of being the first planet to be discovered orbiting another sun-like star. The discovery sent shock waves through the astronomical community, not only for the fact that it was one of the first exoplanets, but because of the unexpected nature of this world. 51 Pegasi b is a massive Jupiter-like planet orbiting at only 0.05 AUs from its sun, far closer than Mercury. At the time, theories of planet evolution allowed giant planets to form only at distances greater than several AU, at about the distance of Jupiter from the sun. To have 51 Pegasi b orbiting so close to its star made astronomers re-examine their theories."
"It wouldn't be so bad if 51 Pegasi b was a rare case. But the discovery of planets orbiting 55 Cancri, tau Bootes, and other sun-like stars have shown that many, maybe even half, of the exoplanets so far discovered are similar to 51 Pegasi b. Although Doppler Spectrography, the technique used to detect these planets, favors massive planets close to their stars over planets further away, these epistellar planets may be quite common."
Tau Bootes b
"Tau Bootes b is one of the most extreme of the so-called 'Hot Jupiters', planets orbiting unusually close to their parent stars. It is both more massive and closer to its star than any of its cousins, such as 51 Pegasi b and 55 Cancri b. Its large mass of 3.87 Jupiters makes tau Bootes b almost certainly a gas giant, and one of the biggest exoplanets yet discovered.
"Another way that tau Bootes b stands out is its parent star. Unlike many of the other parent stars of exoplanets, Tau Bootes is an F type star, making it much hotter and brighter than more Sun-like stars. The combination of closer orbit, higher mass (meaning higher internal temperature), and hotter star makes it highly probable that tau Bootes b has the highest surface temperature of any known planet. The temperature may be so high that it is questionable whether the planet's atmosphere could survive.
"In such hostile environs, tau Bootes b may be slowly evaporating into space. This would make the planet appear hazy and featureless as the departing gases obscure the surface clouds. Both Saturn and Uranus have the same kind of featureless surfaces due to obscuring smog, although not for the same reason. The lost gases may also settle into a cloud around tau Bootes, or it may be blown out of the system entirely by stellar winds. The gas may even trail behind the planet in a faint comet-like tail."
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