A study led by Beth Biller of the University of Arizona reveals that large gaseous planets (like our own Jupiter) stay close to their parent star. The study shows that is very rare for gas giants to be located far away from its host star.
This new study helps scientists to better develop models and theories of how planets form. Some theories suggest that large gas planets are formed far away from a star, and then are slowly pulled in by the star's gravity into a closer orbit.
Of the 246 planets discovered outside of our solar system, many of them are gas giants, 'Hot Jupiters,' that are very large and orbit their parent star in a few days or even hours. These extrasolar planets were detected using the radial velocity method which measures the pull-and-tug between the close orbiting gas giant and the star.
To find gas giants far away from the host star, Beth Biller and her fellow scientists conducted a three-year survey of 54 near and young stars that were thought to have giant gas planets still in their formation process.
Theory says that young 'Jupiters' are brighter than older Jupiters, hence they are more easy to detect. The research found that there were no gas giants that orbited a star at a distance of more than 10 AU ( 1 AU is the distance from the Earth to the Sun) leading the researchers to conclude that it is very rare for gas giants to be located in the outer parts of the solar system.
But Alan Boss, a planetary formation theorists points out a potential flaw in this study, "This survey depends on assuming that young gas giants are much brighter than older gas giants and hence easier to detect." So some Jupiters might exists in the outskirts of solar systems, but are too difficult to detect.
Original Article: Space.com
Jupiter is small compared to the many very large hot Jupiters that are found in other solar systems. Image Credit: NASA