stars of common age. For a random sample of field stars, however, the primary variable determining the likelihood of debris is stellar age [@kains2011].

The correlation in radial velocity studies of giant planet frequency with stellar mass [@fischer2005; @gaidos2013] is another line of evidence connecting planet formation efficiency to stellar mass. The claim is that while $\sim$14% of A stars have one or more $>1 M_\mathrm{Jupiter}$ companions at $<$5 AU, only $\sim$2% of M stars do (@johnson2010, c.f. @lloyd2013 [@schlaufman2013]).

Consistently interpreted as indicators of hidden planets, debris disks finally had their long-awaited observational connection to planets with the watershed discovery of [*directly imaged*]{} planetary mass companions. These were – like the debris disks before them – found first around intermediate-mass A-type stars, rather than the solar-mass FGK-type stars that had been the subject of much observational work at high contrast during the 2000s. HR 8799 [@marois2008; @marois2010] followed by Fomalhaut [@kalas2008] and $\beta$ Pic [@lagrange2009; @lagrange2010] have had their planets [*and indeed one planetary system*]{}, digitally captured by ground-based and/or space-based high contrast imaging techniques. Of the known [*bona fide*]{} planetary mass ($< 10 M_\text{Jup}$) companions that have been directly imaged, six of the nine are located around the 