The perfect 30-min cadence of the full-frame images from the Transiting
Exoplanet Survey Satellite (TESS) will impose a hard Nyquist limit of 24
d−1 (≈278μHz). This will be problematic for asteroseismology
of stars with oscillation frequencies at or around that Nyquist limit, which
will have insurmountable Nyquist ambiguities. TESS does offer some observing
slots at shorter cadences, but these will be limited in number and competitive,
while the full frame images will be the main data product for many types of
variable stars. We show that the Nyquist ambiguities can be alleviated if, when
TESS resumes observations after a downlink, integrations are not resumed at
perfect cadence with those before the downlink. The time spent idling before
integrations are resumed need only be around five minutes for satisfactory
results, and observing time can be recouped from the downlink event if the
telescope does not wait for a return to perfect cadence before resuming
integrations. The importance of imperfect cadence after downlink is discussed
in light of phase coverage of transit events.Comment: 7 pages; 9 figures, all of which use colour but have been checked for
readability under grey-scale printing; 2 small tables; accepted for
publication in MNRA
