Drake multiplied the number of sunlike stars in our galaxy that form each year by a handful of variables: the fraction of those stars that have planets; the number of planets per planetary system where life could exist; the fraction of habitable planets where life actually arises; the fraction of those where intelligence emerges; the fraction of intelligent species that develop interstellar communication; and finally, the average length of time that those communicating civilizations survive. (discovermagazine.com)
White dwarfs are the slowly cooling cores of sunlike stars in which nuclear fusion has stopped. (sciencemag.org)
When Kepler launched into orbit in 2009 to survey a patch of sky containing some 150,000 stars, one of its primary goals was to find mirror Earths, worlds about the same size as our own in approximately 365 - day orbits around sunlike stars. (scientificamerican.com)