More to come
This discovery brings the total known collection of extrasolar planets to 41. Within moments of its formal announcement in Manchester on August 7th it is expected that a number of additional discoveries will be announced from the very same podium. Dr. Michael Mayor of Geneva Observatory will announce the discovery of 7 new planets. The veteran planet hunting team of Dr. Geoffrey Marcy (UC Berkeley) and Dr. Paul Butler (Carnegie Institution of Washington) will announce the discovery of 3 new planets (one of which is also cited by Dr. Mayor). Combined with the announcement of the planet circling Epsilon Eridani, this will cause the known collection of extrasolar planets to grow to 50.
In addition to announcing these 10 new worlds, it will also be revealed that one of these bodies is rather small (comparatively speaking) with a size very close to that of Saturn. In addition, research will be presented that suggests that many previously identified extrasolar planets appear to inhabit solar systems with more than one planet.
Persistence pays off
Suspicions have been held about planets circling Epsilon Eridani for quite some time. In 1974, Peter van de Camp published an article "Parallax and Orbital Motion of Epsilon Eridani" wherein he stated that "the star appears to have a perturbation with a period of 25 yr and a semimajor axis of 0."0191 + 0."0018; the mass of the unseen companion has a minimum value of 0.0006Msol." This article was published after making 900 photos of Epsilon Eridani on 238 nights over the interval 1938-1972.
Planet hunting is not a new pursuit by any means. However, the tools have gotten better. None the less, persistence is still a prerequisite.
In a press release issued by the International Astronomical Union, William Cochran said "the discovery of the new planet circling Epsilon Eridani raises the tantalizing possibility of detecting planets with longer orbital periods and of detecting multiplanet systems like the solar system. Epsilon Eridani is located in one of the 10 nearest star systems and is bright enough to be seen with the naked eye. "You can go outside at night, even in Austin, and point at it and say that star there has a planet around it," Cochran said."
There will be a few extra people looking skyward tonight.