After the announcement of the discovery of 55 Cancri f, which marks a new ground in exoplanetary search by making of 55 Cancri the first star known to have a system of 5 confirmed planets, spacEurope contacted the lead author of the paper where this results are announced, astronomer Debra Fischer, San Francisco State University.

It was a happy astronomer who grabbed the questions that were on the table and that kindly gave us her answers.

I started by asking Debra Fischer if the host star, 55 Cancri would now just stay quiet or would it keep on surprising us by revealing an even larger planetary family, having additional farer planets, the astronomer told spacEurope that “it is certainly possible that 55 Cancri could have additional planets beyond the one we just found. There is a large, "empty" gap between this 45 earth-mass planet at 0.78 AU and the most distant 4 jupiter-mass planet at 5.7 AU.

And the possibility of finding planets among the already discovered? According to our guest “it will be up to the dynamicists to model this system and see if another one would fit in the habitable zone of 55 Cancri.” But this might be something improbable and, as Fischer remarks, it is probably also difficult to fit another planet inside of the one we just found because there are already 3 big planets in the area...

"Because 55 Cancri has multiple planets, the star had to be observed for a long time before astronomers could find and confirm its fifth planet. These data were collected over a period of 18 years using both the Lick Observatory near San Jose, Calif., and the W.M. Keck Observatory in Hawaii." Click image to enlarge. Image Credit: NASA/JPL-Caltech/SFSU

Having in mind the multitude of so different and, astrobiologically speaking, interesting moons orbiting the giant planets out of the habitable zone in our system I was curious to know hat would be the consequences of the existence of moons around this planet, since it is located exactly on the habitable zone? Just imagine Titan, Enceladus or Europa in a cozy environment...

Our guest tells that there are no evidence at all for a moon orbiting the new planet and if there were one it would not be detectable, but she gives her insight into what might make this an interesting site for life...a moon orbiting 55 Cancri f would need to be at least the size of Mars, with enough mass to hang on to an atmosphere and oceans of water.

And after this discovery? Where is Debra Fischer aiming at? Will her future observations continue to be dedicated to 55 Cancri? The answer is clear, this system will have no rest...the astronomer tells us that the team will “definitely keep looking at this system, refining the orbits and searching for signals from other planets.
As Fischer remembers, there is no time to sleep over the success, in her words they “work hard for every scrap of improvement”, the only way that might lead to improvements that will give the team “even more precise measurements, enabling the detection of still more planets”.
If there’s life around 55 Cancri, those fiftyfivecancriefers might be getting that strange impression of being observed...

"This wide-angle photograph of the night sky shows the location of 55 Cancri."

Click image to enlarge.

Image Credit: Till Credner, AlltheSky.com

But space is a BIG place and this specific star and its system are just the first of a kind, exoplanets are starting to look like mushrooms in early Autumn...and where does this discovery lead astronomers to? Yes...you are right...to discover even more!
Fischer tells us that astronomers “now need to look more carefully at all of the other stars with planets and spacEurope’s guest would personally like to know if they are also "packed" with planets that astronomers have just missed because the masses are so low.

And, the expectations about the bright, glorious path ahead for exoplanetary search with current and future telescopes?

Debra Fischer excitment goes towards the James Webb Space Telescope (JWST), the a large, infrared-optimized space telescope, scheduled for launch in 2013 and that will find the first galaxies and will be able to stars forming planetary systems.
In the astronomer’s perspective, there is a wonderful foundation of planetary systems from the Doppler technique, but we need space missions to find Earths.
That is why Fischer deposits so much confidence in JWST, in her words the telescope “will contribute in ways that we can't even imagine”...

A reference to other missions is made, our guest’s opinion is that ESA’s Corot; which will make an announcement on its discoveries within a month (Dec 10) and NASA’s Kepler, to be launched on February 2009, will give us incredible windows into other planetary systems.
Also a spaceborn astrometry mission would be, in Fischer’s view, an excellent way to see planets but these missions are so expensive, that the astronomer hopes that resources can be pooled across the world, that would be the way to make great progress, working together.