Featured Research

from universities, journals, and other organizations

Newfound Planetary System Has "Hometown" Look

Date:
June 14, 2002
Source:
National Science Foundation
Summary:
After 15 years of observation and a lot of patience, the world's premier planet-hunting team has found a planetary system that reminds them of our home solar system.

After 15 years of observation and a lot of patience, the world's premier planet-hunting team has found a planetary system that reminds them of our home solar system.

Geoffrey Marcy, astronomy professor at the University of California, Berkeley, and astronomer Paul Butler of the Carnegie Institution of Washington, today announced the discovery of a Jupiter-like planet orbiting a Sun-like star at nearly the same distance as the Jovian system orbits our sun.

"All other extrasolar planets discovered up to now orbit closer to the parent star, and most of them have had elongated, eccentric orbits. This new planet orbits as far from its star as our own Jupiter orbits the sun,” said Marcy. The National Science Foundation (NSF) and NASA fund the planet-hunting team.

The star, 55 Cancri in the constellation Cancer, was already known to have one planet, announced by Butler and Marcy in 1996. That planet is a gas giant slightly smaller than the mass of Jupiter and whips around the star in 14.6 days at a distance only one-tenth that from Earth to the sun.

Using as a yardstick the 93-million mile Earth-sun distance, called an astronomical unit or AU, the newfound planet orbits at 5.5 AU, comparable to Jupiter's distance from our sun of 5.2 AU (about 512 million miles). Its slightly elongated orbit takes it around the star in about 13 years, comparable to Jupiter's orbital period of 11.86 years. It is 3.5 to 5 times the mass of Jupiter.

"We haven't yet found an exact solar system analog, which would have a circular orbit and a mass closer to that of Jupiter. But this shows we are getting close, we are at the point of finding planets at distances greater than 4 AU from the host star,” said Butler.

“I think we will be finding more of them among the 1,200 stars we are now monitoring," he added.

The team shared its data with Greg Laughlin, assistant professor of astronomy and astrophysics at the University of California, Santa Cruz. His dynamical calculations show that an Earth-sized planet could survive in a stable orbit between the two gas giants. For the foreseeable future, existence of any such planet around 55 Cancri will remain speculative.

Marcy, Butler and their team also announced a total of 15 new planets today, including the smallest ever detected: a planet circling the star HD49674 in the constellation Auriga at a distance of .05 AU, one-twentieth the distance from Earth to the sun. Its mass is about 15 percent that of Jupiter and 40 times that of Earth. This brings the total number of known planets outside our solar system to 91.

Discovery of a second planet orbiting 55 Cancri culminates 15 years of observations with the 3-meter (118-inch) telescope at Lick Observatory, owned and operated by the University of California. The team also includes Debra Fischer, UC Berkeley; Steve Vogt, UC Santa Cruz; Greg Henry, Tennessee State University, Nashville; and Dimitri Pourbaix, the Institut d'Astronomie et d'Astrophysique, Universitι Libre de Bruxelles.

Marcy and Butler used a technique that measures the slight Doppler shift in starlight caused by a wobble in the star’s position, due to the gravitational tug of an orbiting planet. By observing over a period of years, they can infer a planet’s approximate mass and orbital size and period.

The star 55 Cancri is 41 light years from Earth and is about 5 billion years old. Further data are needed to determine whether yet another planet is orbiting it, because the two known planets do not explain all the observed Doppler wobbling. One possible explanation is a Saturn-mass planet orbiting about .24 AU from the star.

For more information, see: http://exoplanets.org

An artist's concept and animation will be available June 13 at: http://www.jpl.nasa.gov/images/newplanets


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Newfound Planetary System Has "Hometown" Look." ScienceDaily. ScienceDaily, 14 June 2002. <www.sciencedaily.com/releases/2002/06/020614075908.htm>.
National Science Foundation. (2002, June 14). Newfound Planetary System Has "Hometown" Look. ScienceDaily. Retrieved July 25, 2014 from www.sciencedaily.com/releases/2002/06/020614075908.htm
National Science Foundation. "Newfound Planetary System Has "Hometown" Look." ScienceDaily. www.sciencedaily.com/releases/2002/06/020614075908.htm (accessed July 25, 2014).

Share This




More Space & Time News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

This Week @ NASA, July 25, 2014

This Week @ NASA, July 25, 2014

NASA (July 25, 2014) — Apollo 11 celebration, Next Giant Leap anticipation, ISS astronauts appear in the House and more... Video provided by NASA
Powered by NewsLook.com
Space to Ground: Coming and Going

Space to Ground: Coming and Going

NASA (July 25, 2014) — One station cargo ship leaves, another arrives, aquatic research and commercial spinoffs. Questions or comments? Use #spacetoground to talk to us. Video provided by NASA
Powered by NewsLook.com
How A Solar Flare Could Have Wrecked Earth's Electronics

How A Solar Flare Could Have Wrecked Earth's Electronics

Newsy (July 25, 2014) — Researchers say if Earth had been a week earlier in its orbit around the sun, it would have taken a direct hit from a 2012 coronal mass ejection. Video provided by Newsy
Powered by NewsLook.com
Raw: ISS Cargo Ship Launches in Kazakhstan

Raw: ISS Cargo Ship Launches in Kazakhstan

AP (July 23, 2014) — The Progress 56 cargo ship launched from the Baikonur Cosmodrome in Kazakhstan Wednesday. NASA says it will deliver cargo and crew supplies to the International Space Station. (July 23) Video provided by AP
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