  In 2007, a companion with planetary mass was found around the pulsating
subdwarf B star V391 Pegasi with the timing method, indicating that a
previously undiscovered population of substellar companions to apparently
single subdwarf B stars might exist. Following this serendipitous discovery,
the EXOTIME (http://www.na.astro.it/~silvotti/exotime/) monitoring program has
been set up to follow the pulsations of a number of selected rapidly pulsating
subdwarf B stars on time-scales of several years with two immediate
observational goals:
  1) determine Pdot of the pulsational periods P
  2) search for signatures of substellar companions in O-C residuals due to
periodic light travel time variations, which would be tracking the central
star's companion-induced wobble around the center of mass.
  These sets of data should therefore at the same time: on the one hand be
useful to provide extra constraints for classical asteroseismological exercises
from the Pdot (comparison with "local" evolutionary models), and on the other
hand allow to investigate the preceding evolution of a target in terms of
possible "binary" evolution by extending the otherwise unsuccessful search for
companions to potentially very low masses. While timing pulsations may be an
observationally expensive method to search for companions, it samples a
different range of orbital parameters, inaccessible through orbital photometric
effects or the radial velocity method: the latter favours massive close-in
companions, whereas the timing method becomes increasingly more sensitive
towards wider separations. In this paper we report on the status of the
on-going observations and coherence analysis for two of the currently five
targets, revealing very well-behaved pulsational characteristics in HS
0444+0458, while showing HS 0702+6043 to be more complex than previously
thought.
