  We present an analysis of debris disk data around Solar-type stars (spectral
types F0-K5) using the steady-state analytical model of Wyatt et al. (2007).
Models are fitted to published data from the FEPS (Meyer et al. 2006) project
and various GTO programs obtained with MIPS on the Spitzer Space Telescope at
24 micron and 70 micron, and compared to a previously published analysis of
debris disks around A stars using the same evolutionary model. We find that the
model reproduces most features found in the data sets, noting that the model
disk parameters for solar-type stars are different to those of A stars.
Although this could mean that disks around Solar-type stars have different
properties from their counterparts around earlier-type stars, it is also
possible that the properties of disks around stars of different spectral types
appear more different than they are because the blackbody disk radius
underestimates the true disk radius by a factor $X_r$ which varies with
spectral type. We use results from realistic grain modelling to quantify this
effect for solar-type stars and for A stars. Our results imply that
planetesimals around solar-type stars are on average larger than around A stars
by a factor of a few but that the mass of the disks are lower for disks around
FGK stars, as expected. We also suggest that discrepancies between the
evolutionary timescales of 24 micron statistics predicted by our model and that
observed in previous surveys could be explained by the presence of
two-component disks in the samples of those surveys, or by transient events
being responsible for the 24 micron emission of cold disks beyond a few Myr.
Further study of the prevalence of two component disks, and of constraints on
$X_r$, and increasing the size of the sample of detected disks, are important
for making progress on interpreting the evolution of disks around solar-type
stars.

Solar and Stellar Astrophysics;Earth and Planetary Astrophysics