Featured Research

from universities, journals, and other organizations

NCAR Scientist's Observations Aid In Discovery Of Multiple Planets Orbiting A Sun-Like Star

Date:
April 16, 1999
Source:
National Center For Atmospheric Research (NCAR)
Summary:
Three planets have been found orbiting the star Upsilon Andromedae in the first discovery of multiple planets outside our solar system. NCAR scientist Timothy Brown was part of the team of eight scientists who observed the additional planets.

BOULDER--Two more planets orbiting a Sun-like star, in addition toone found three years ago, have emerged from data analyzed bythree teams of scientists at San Francisco State University, theHarvard-Smithsonian Center for Astrophysics (CfA), and the NationalCenter for Atmospheric Research (NCAR). This is the first time thatmultiple planets have been discovered around a Sun-like star.

A team of astronomers including Timothy Brown of NCAR has beenobserving the star, known as Upsilon Andromedae, since 1996, whenits first planet was discovered. When the CfA/NCAR observationswere added to those of that planet's discoverers, Geoffrey Marcy andPaul Butler of San Francisco State University, the scientists confirmedthat our solar system isn't the only one with more than one planet.The NCAR observations were funded by the National ScienceFoundation, NCAR's primary sponsor.

Butler (now at the Anglo-Australian Observatory) and Marcy havesubmitted a paper to the Astrophysical Journal, with Brown as one ofthe coauthors, describing the evidence that two additional planetsare orbiting Upsilon Andromedae.

The discovery of multiple planets "has something to say about theway solar systems can form," Brown says. "There's not just one bigobject slurping up all the mass" in a planetary system, as some havetheorized. It's not clear whether Upsilon Andromedae's three planetsformed at their current orbital distances or formed elsewhere andmigrated after some catalytic event, such as a close encounterbetween two planets or the passing of another star.

The scientists analyzed independent observations of the star fromtwo locations: Lick Observatory (operated by the University ofCalifornia) and Whipple Observatory (operated by the SmithsonianAstrophysical Observatory). When the teams eliminated the effectsof the 4.6-day orbital period of the known planet from the data,another period of about 1,200 days sprang into view. Calculationssuggested it was caused by a planet four times the mass of Jupiter,the largest planet in our solar system. This new planet circled at adistance of about 2.5 astronomical units from its star. Anastronomical unit (AU) is the distance from the Earth to the Sun, or93 million miles. The original planet is about three-quarters the massof Jupiter, orbiting at a distance of only 4.7 million miles--muchcloser to its star than Mercury is to the Sun.

"After removing the effects of both the 4-day period and the 1,200-day period, the observations still had bigger-than-expected noise,"Brown says. The scientists then pinpointed a third planet, abouttwice the mass of Jupiter, orbiting in about 250 days at a distanceslightly under 1 AU.

At a meeting last June, team members from NCAR and CfA met withGeoff Marcy and indicated that they thought another planet waspresent. Marcy agreed and suggested joining forces to find it. "Wewere both wrong, in a way," says Brown. "We thought we had foundone new planet, but in fact we had two."

About twenty extrasolar planets have been discovered by observingtheir gravitational pull on their stars. All stars move through space,but a star with a big, close planet also wobbles as the circling planettugs it out of its path. To an observer on Earth, the star's lightappears to waver slightly. "The method is very biased toward findingbig planets close to their stars," Brown says. "If we were on anextrasolar planet observing our own solar system, "we wouldn't evenfind Jupiter--much less the Earth--by our method, because Jupiter isso far from the Sun," he points out.

NCAR is managed by the University Corporation for AtmosphericResearch, a consortium of more than 60 universities offering Ph.D.s inatmospheric and related sciences.

-The End-

Writer: Carol Rasmussen


Story Source:

The above story is based on materials provided by National Center For Atmospheric Research (NCAR). Note: Materials may be edited for content and length.


Cite This Page:

National Center For Atmospheric Research (NCAR). "NCAR Scientist's Observations Aid In Discovery Of Multiple Planets Orbiting A Sun-Like Star." ScienceDaily. ScienceDaily, 16 April 1999. <www.sciencedaily.com/releases/1999/04/990415142330.htm>.
National Center For Atmospheric Research (NCAR). (1999, April 16). NCAR Scientist's Observations Aid In Discovery Of Multiple Planets Orbiting A Sun-Like Star. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/1999/04/990415142330.htm
National Center For Atmospheric Research (NCAR). "NCAR Scientist's Observations Aid In Discovery Of Multiple Planets Orbiting A Sun-Like Star." ScienceDaily. www.sciencedaily.com/releases/1999/04/990415142330.htm (accessed August 1, 2014).

Share This




More Space & Time News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Supply Ship Takes Off for International Space Station

Supply Ship Takes Off for International Space Station

AFP (July 30, 2014) The European Space Agency's fifth Automated Transfer Vehicle (ATV-5) is takes off to the International Space Station on an Ariane 5 rocket from French Guiana. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Raw: Rocket Launches Into Space With Cargo Ship

Raw: Rocket Launches Into Space With Cargo Ship

AP (July 30, 2014) Arianespace launched a rocket Tuesday from French Guiana carrying a robotic cargo ship to deliver provisions to the International Space Station. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Russia Saves Gecko Sex Satellite, Media Has Some Fun With It

Newsy (July 27, 2014) The satellite is back under ground control after a tense few days, but with a gecko sex experiment on board, the media just couldn't help themselves. 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:
from the past week

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