Featured Research

from universities, journals, and other organizations

Rapid-born Planets Present 'Baby Picture' Of Our Early Solar System

Date:
September 11, 2005
Source:
University of Rochester
Summary:
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. The new findings 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.

Artist's conception: Planets sweep away a clearing in mass of dust surrounding a fledgling star. (NASA/JPL-Caltech)

Using NASA's Spitzer Space Telescope, a team of astronomers led by theUniversity of Rochester has detected gaps ringing the dusty disksaround two very young stars, which suggests that gas-giant planets haveformed there. A year ago, these same researchers found evidence of thefirst "baby planet" around a young star, challenging mostastrophysicists's models of giant-planet formation.

The new findings in the Sept. 10 issue of Astrophysical JournalLetters not only reinforce the idea that giant planets like Jupiterform much faster than scientists have traditionally expected, but oneof the gas-enshrouded stars, called GM Aurigae, is analogous to our ownsolar system. At a mere 1 million years of age, the star gives a uniquewindow into how our own world may have come into being.

"GM Aurigae is essentially a much younger version of our Sun, and thegap in its disk is about the same size as the space occupied by our owngiant planets," says Dan Watson, professor of physics and astronomy atthe University of Rochester and leader of the Spitzer IRS Disksresearch team. "Looking at it is like looking at baby pictures of ourSun and outer solar system," he says.

"The results pose a challenge to existing theories ofgiant-planet formation, especially those in which planets build upgradually over millions of years," says Nuria Calvet, professor ofastronomy at the University of Michigan and lead author of the paper."Studies like this one will ultimately help us better understand howour outer planets, as well as others in the universe, form."

The new "baby planets" live within the clearings they have scoured outin the disks around the stars DM Tauri and GM Aurigae, 420 light yearsaway in the Taurus constellation. These disks have been suspected forseveral years to have central holes that might be due to planetformation. The new spectra, however, leave no doubt: The gaps are soempty and sharp-edged that planetary formation is by far the mostreasonable explanation for their appearance.

The new planets cannot yet be seen directly, but Spitzer'sInfrared Spectrograph (IRS) instrument clearly showed that an area ofdust surrounding certain stars was missing, strongly suggesting thepresence of a planet around each. The dust in a protoplanetary disk ishotter in the center near the star, and so radiates most of its lightat shorter wavelengths than the cooler outer reaches of the disk. TheIRS Disks team found that there was an abrupt deficit of lightradiating at all short infrared wavelengths, strongly suggesting thatthe central part of the disk was absent. These stars are very young bystellar standards, about a million years old, still surrounded by theirembryonic gas disks. The only viable explanation for the absence of gasthat could occur during the short lifetime of the star is that aplanet--most likely a gas giant like our Jupiter--is orbiting the starand gravitationally "sweeping out" the gas within that distance of thestar.

As with last year's young-planet findings, these observationsrepresent a challenge to all existing theories of giant-planetformation, especially those of the "core-accretion" models in whichsuch planets are built up by accretion of smaller bodies, which requiremuch more time to build a giant planet than the age of these systems.

The IRS Disks team discovered something else curious about GMAurigae. Instead of a simple central clearing of the dust disk, as inthe other cases studied, GM Aurigae has a clear gap in its disk thatseparates a dense, dusty outer disk from a tenuous inner one. Thiscould be either an intermediate stage as the new planet clears out thedust surrounding it and leading to a complete central clearing like theother "baby planet" disks, or it could be the result of multipleplanets forming within a short time and sweeping out the dust in a morecomplex fashion.

GM Aurigae has 1.05 times the mass of our Sun-a near twin--soit will develop into a star very similar to the Sun. If it wereoverlaid onto our own Solar System, the discovered gap would extendroughly from the orbit of Jupiter (460 million miles) to the orbit ofUranus (1.7 billion miles). This is the same range in which thegas-giant planets in our own system appear. Small non-gas-giantplanets, 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 builtSpitzer's Infrared Spectrograph, and includes astronomers at theUniversity of Rochester, Cornell University, the University ofMichigan, the Autonomous National University of Mexico, the Universityof Virginia, Ithaca College, the University of Arizona, and UCLA.NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages theSpitzer Space Telescope mission for NASA's Science Mission Directorate,in Washington. Science operations are conducted at the Spitzer ScienceCenter at the California Institute of Technology, also in Pasadena.


Story Source:

The above story is based on materials provided by University of Rochester. Note: Materials may be edited for content and length.


Cite This Page:

University of Rochester. "Rapid-born Planets Present 'Baby Picture' Of Our Early Solar System." ScienceDaily. ScienceDaily, 11 September 2005. <www.sciencedaily.com/releases/2005/09/050910085540.htm>.
University of Rochester. (2005, September 11). Rapid-born Planets Present 'Baby Picture' Of Our Early Solar System. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2005/09/050910085540.htm
University of Rochester. "Rapid-born Planets Present 'Baby Picture' Of Our Early Solar System." ScienceDaily. www.sciencedaily.com/releases/2005/09/050910085540.htm (accessed October 22, 2014).

Share This



More Space & Time News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Comet Siding Spring Grazes Mars' Atmosphere

Comet Siding Spring Grazes Mars' Atmosphere

Newsy (Oct. 19, 2014) A comet from the farthest reaches of the solar system passed extremely close to Mars this weekend, giving astronomers a rare opportunity to study it. Video provided by Newsy
Powered by NewsLook.com
Latin America Launches Communications Satellite

Latin America Launches Communications Satellite

AFP (Oct. 17, 2014) Argentina launches a home-built satellite, a first for Latin America. It will ride a French-made Ariane 5 rocket into orbit, and will provide cell phone, digital TV, Internet and data services to the lower half of South America. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
This Week @ NASA, October 17, 2014

This Week @ NASA, October 17, 2014

NASA (Oct. 17, 2014) Power spacewalk, MAVEN’s “First Light”, Hubble finds extremely distant galaxy and more... Video provided by NASA
Powered by NewsLook.com
Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Saturn's 'Death Star' Moon Might Have A Hidden Ocean

Newsy (Oct. 17, 2014) The smallest of Saturn's main moons, Mimas, wobbles as it orbits. Research reveals it might be due to a global ocean underneath its icy surface. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins