When we are going to approach to the binary system Kepler-16 (image source) we'll see two different stars: the largest of the couple, the star A, is a K dwarf with a mass of about 0.69 solar mass and about 0.65 Sun's radius, and a little red dwarf, the stra B, with a mass of about 0.2 solar mass and about 0.23 Sun's radius. But when we'll arrive at about 0.5 au from the gravitational centre of the binary system we'll see a great surprise: a little planet with a mass of 0.333 ± 0.016 and a radius of 0.7538 ± 0.0025 those of Jupiter(1).
In this momenti is very difficult to suppose the properties(2) (like composition and surface temperature) of Kepler-16b, but the most important thing is that Kepler can discover, using the transit technique, also a planet around a binary system! I think that this is the principle reason becuase the paper was accepted by Science. And it's clear that all nerd and sci-fi fan think about Skywalker family's planet, Tatooine:
Press release: Nasa, Kepler
Two interesting posts from SETI by Laurance Doyle and Franck Marchis
(1) Doyle, L., Carter, J., Fabrycky, D., Slawson, R., Howell, S., Winn, J., Orosz, J., Pr sa, A., Welsh, W., Quinn, S., Latham, D., Torres, G., Buchhave, L., Marcy, G., Fortney, J., Shporer, A., Ford, E., Lissauer, J., Ragozzine, D., Rucker, M., Batalha, N., Jenkins, J., Borucki, W., Koch, D., Middour, C., Hall, J., McCauliff, S., Fanelli, M., Quintana, E., Holman, M., Caldwell, D., Still, M., Stefanik, R., Brown, W., Esquerdo, G., Tang, S., Furesz, G., Geary, J., Berlind, P., Calkins, M., Short, D., Steffen, J., Sasselov, D., Dunham, E., Cochran, W., Boss, A., Haas, M., Buzasi, D., & Fischer, D. (2011). Kepler-16: A Transiting Circumbinary Planet Science, 333 (6049), 1602-1606 DOI: 10.1126/science.1210923 (pdf)
(2) In the paper we can read that the high density suggests a greater degree of enrichment by heavy elements. At the other hand
Nevertheless, for any age greater than 0.5 Gyr, the planet’s interior would include 40-60 Earth masses of heavy elements according to standard planetary models(3). This would imply a composition of approximately half gas (hydrogen and helium) and half heavy elements (presumably ice and rock).So I think that is not so correct write in press release
Kepler-16b is cold, gaseous and not thought to harbor lifealso because
it more difficult to estimate the age [of star A] with theoretical evolutionary modelsThe surface temperature (170-200 K), instead, seems more certain.
In every case Kepler-16b is a death planet...
(3) Fortney, J.J., et al., Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits, Astroph. J., 659, 1661-1672 (2007)