V455 And = HS2331, as you all know, is having an outburst for the ages.
   The coverage is almost as good as that of WZ Sge in 2001, and vastly
 better than any other dwarf nova in history.  It's great to have bright
 eruptions from stars transiting near local midnight, and in this case
 with many periodic clocks to study the effects of outburst.

 A few of you are obtaining multicolor data; except possibly for the very
 beginning of outburst, there appear to be no significant color effects
 in the star.  It's basically a big blue light bulb, and the main reasons
 for observing it filtered are these:

 (1) Archival.  With V data, it's possible to say meaningfully "how
      bright it is".

 (2) (Differential) extinction.  Through a very wide or no filter, a CV's
      extinction always exceeds that of the comparison star, introducing
      unwanted waves in long light curves.

 (2) is an item of some consequence, and worth doing if you can afford
 the roughly 6x loss of photons (in which case V is probably the best
 choice).  But I tend to be skeptical about (1).  CVs are forever
 variable anyway, and there is likely no significance to their exact
 brightness.  *Someone* needs to do V measurements; and everyone - even
 unfiltered diehards - needs to make an estimate of the brightness level.
 But the sensitivity of time series to periodic signals is greatly
 improved by a healthy count rate.  So for our purposes, unfiltered
 generally wins.  Exceptions are a very bright star (like V455 And the
 last 2 weeks!) and an interest in timescales natural to extinction (say
 6-24 hours).

 There's another very specialized reason that applies to this star.  It
 has strong 68 and 34 second signals at quiescence.  Their origin is
 still unclear, but we FERVENTLY would like to measure how they are
 affected by the outburst.  So we need quite short integrations.  To
 resolve both, you need a cycle time (integration + dead time) of <17 s,
 or let's say 13 s to be more comfortable.  Can you do that?  I think for
 most of you the answer is no; if that's true, try for ~20 s, which will
 fail to resolve the harmonic properly, but do a decent job on the
 fundamental.  Avoid, however, cycle times very close to 17 s and 34 s;
 when the period is an exact multiple of the sampling time, terrible
 things happen!  (Like trying to measure the Earth's rotation period with
 brightness measures at noon and midnight every day!)

 For the moment, V455 And is certainly the best northern object.  To say
 the least.