2013MNRAS.436..650P

We determine the fraction of G dwarf stars that could host stable planetary systems based on the observed properties of binaries in the Galactic field, and in various postulated primordial binary populations, which assume that the primordial binary fraction is higher than that in the field. We first consider the frequency of Solar system analogues - planetary systems that form either around a single G dwarf star or a binary containing a G dwarf where the binary separation exceeds 100-300au. If the primordial binary fraction and period distribution are similar to those in the field, then up to 63 percent of G dwarf systems could potentially host a Solar system analogue. However, if the primordial binary fraction is higher, the fraction of G dwarf systems that could host a planetary system like our own is lowered to 38 percent.

We extend our analysis to consider the fraction of G dwarf systems (both single and binary) that can host either circumprimary planets (orbiting the primary star of the binary) or circumbinary planets (orbiting both stars in the binary) for fiducial planetary separations in the range 1-100au. Depending on the assumed binary population, in the circumprimary case between 65 and 95 percent of systems can host a planet at 1au, decreasing to between 20 and 65 percent of systems that can host a planet at 100au. In the circumbinary case, between 5 and 59 percent of systems can host a planet at 1au, increasing to between 34 and 75 percent of systems that can host a planet at 100au.

Our results suggest that the assumed binary fraction is the key parameter in determining the fraction of potentially stable planetary systems in G dwarf systems and that using the present-day value may lead to significant overestimates if the binary fraction was initially higher.