  WR140 (WC7pd + O5) is often considered to be the archetype of hot, luminous
colliding-wind binaries, with strong cyclic high-energy and dust-formation
events. The challenge is that this system is quite extreme, with a long period
(nearly an integral 7.94 years) and high eccentricity (e = 0.88). Most of the
action thus occurs during the relatively short several-month interval of close
periastron passage, which in the most recent 2009 January passage occurred
during the northern winter months when this summer Cygnus star was least
favourably placed in the sky for groundbased observation. To meet this
challenge, various multiwavelength campaigns were organized at different sites
and from space, mainly within several months of periastron passage 2009. Of
particular interest to this workshop was the MONS optical spectroscopic effort,
involving both amateur and professional astronomers at the MONS site on
Tenerife from 2008 December through 2009 March. I will describe WR140 in terms
of the general phenomenon of hot colliding winds and leave the new campaign
details to other speakers at this workshop.
