[Aavso-photometry] CI CYG Time Series Interval

[arne]

Richard Harvan wrote:
> Dear All,
>         I obtained a time series of CI CYG last night.  What is a good interval between measurements?  I have seen on this discussion group that 10 minutes is fine for a time series.   I can go significantly shorter, down to 2 minute interval, which I have done for RR LYR/DSCT types.
>  
Hi Rich,
The interval for a specific star depends on the expected rapidity of the
variation.  My usual guideline is 100 datapoints on the lightcurve of a
regular variable, such as a pulsator (Mira, Cepheid) or eclipsing
binary.  For cataclysmics or symbiotic stars, where flickering occurs,
you can't really pick a minimum time interval - there is variation at
all time scales.  Then it depends on your instrumental setup.

I usually try to get signal/noise of 50 per exposure, so that any
detected variation is real.  Sometimes this is not possible: the
object is too faint, so that exposures are so long that you wash out
the short-period variation; sometimes you end up with 1-second exposures
with 10-second readout deadtime, so your sky efficiency is low; etc.

With CI Cyg, anything goes.  Fast or slow, your data will have value.
Arne