Skyguy
07-14-2005, 07:18 PM
If it's clear tonight, go outside and pick a star... any star. Odds are, you're really looking at two or more in a binary system.
Actually, most stars live out their lives in multiple systems. However, for two major reasons, exo-planet hunters have tended to avoid stars in close multiple systems in their search for other worlds. Why??
#1. Practical:
-Trying to detect a planet orbiting a single star isn't easy to begin with. The gravitational effects of any close neighbours would make finding the tell-tale wobble of a nearby star+planet even more difficult to distinguish.
#2. Theoretical:
-'The numbers' would seem to indicate that stars in close systems should inhibit the creation, or at least - the long term survival - of planets.
Those two reasons might soon be thrown out the window now that Dr. Maciej Konacki (Cal. Tech.) has found an improbable planet orbiting around a star in the multiple system HD 188753.
The planet itself is thought to be another "hot Jupiter", or "Roaster" as they're sometimes called, and has been named HD 188753 Ab. It orbits the primary star of the system every 3.3 days. In turn, a pair of stars orbit the primary star every 25.7 years - and 'dance' around each other every 153 days.
Have a look at this NASA site for more info & a QuickTime animation of this interesting triple star system....
http://www.jpl.nasa.gov/news/news.cfm?release=2005-115
Actually, most stars live out their lives in multiple systems. However, for two major reasons, exo-planet hunters have tended to avoid stars in close multiple systems in their search for other worlds. Why??
#1. Practical:
-Trying to detect a planet orbiting a single star isn't easy to begin with. The gravitational effects of any close neighbours would make finding the tell-tale wobble of a nearby star+planet even more difficult to distinguish.
#2. Theoretical:
-'The numbers' would seem to indicate that stars in close systems should inhibit the creation, or at least - the long term survival - of planets.
Those two reasons might soon be thrown out the window now that Dr. Maciej Konacki (Cal. Tech.) has found an improbable planet orbiting around a star in the multiple system HD 188753.
The planet itself is thought to be another "hot Jupiter", or "Roaster" as they're sometimes called, and has been named HD 188753 Ab. It orbits the primary star of the system every 3.3 days. In turn, a pair of stars orbit the primary star every 25.7 years - and 'dance' around each other every 153 days.
Have a look at this NASA site for more info & a QuickTime animation of this interesting triple star system....
http://www.jpl.nasa.gov/news/news.cfm?release=2005-115