[Aavso-photometry] Var Her 04 Update: No more superhumps?

[Aaron Price]

 (At the end is a copy of a Special MyNewsFlash notice for those not
subscribed to the MyNewsFlash service.)

 I had every intention of actually recommending that tired observers take
tonight off to rest up and relax for a heavy observing run this weekend.
But, alas, the best laid plans of mice and men...

 Now that superhumps have vanished we need observations as much as ever to
see if they return. Unfiltered is fine, and probably required at this
level of brightness.

ANOTHER unknown dwarf novae outburst??
 V1316 Cyg is a dwarf nova of unknown type. Mike Simonsen reported it in
outburst on the 29th. Time series observations looking for superhumps and
other behavior is needed to help ID the type. If you want to take a step
away from Var Her 04 for a moment, a few hours on this star could be
useful. But try to get at least a few hours on Var Her 04 first - it has
priority seating at the table. :)  Charts with CCD photometry are online
here: http://www.aavso.org/cgi-bin/searchcharts3.pl?name=v1316%20cyg
Latest obs:  V1316 CYG  JUN 29.2986 2453185.7986  15.0   SXN   Y

 Administrivia Note: I will be on vacation until Monday evening. Parents
are visiting for the holiday weekend so it will be a "real"  vacation
meaning that little work will get done as opposed to simply working from a
new location. I will still endevour to make a post and update the web page
light curves once per day, but I can't guarantee it. I've asked Tonny to
post updates if he notices anything abnormal and I'm not around to put out
an update.

Aaron
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Subject: Special MyNewsFlash: Var Her 04 Disappearing Superhumps - Visual &
         CCD Observations Needed

Disappearing Superhumps!
 Var Her 04 continues to be an interesting object. Around 06 UT
on July 1 (2453187.75) superhumps disappeared from the light
curve and have been replaced with a 27 minute hump with an
amplitude (estimated visually) of around 0.2 magnitudes! BVR
data from Arne Henden (USNO) and BV data from Donn Starkey
illustrates the shift in this light curve:
           http://www.aavso.org/news/varher04lc-9.png
 Fourier plus CLEANEST analysis puts the new period at 0.0289
+/- 0.0006 days. Updates, light curves and additional
information are all available at this web page:
           http://www.aavso.org/news/her04.shtml

Visual Observers:
  If this is indeed a UGWZ object (which is by no means
certain), then a rebrightening phase will be expected this
weekend. From Friday-Monday intensive visual monitoring of Var
Her 04 is needed. Please observe it at the start and again at
the end of your observing session. Right now it is faint
(~15-16th V magnitude) but a rebrightening episode could reach
13.5 - 14th magnitude. If you detect such a rebrightening
please report it to the AAVSO and to this discussion group as
soon as you can (ie run inside!). It is important that we get
good coverage during the rebrightening phase which will
probably last only a portion of a day (perhaps 12 hours or
less).
  New charts with more comparison stars have been published
here:
http://www.aavso.org/cgi-bin/searchcharts3.pl?name=var%20her%2004

CCD Observers:
  BVR photometry is needed during the rebrightening phase to
look for changes in color, temperature and test some modeling
of the mechanism behind these echo outbursts. In addition, we
need to look for evolution in these humps and for the possible
reemergence of orbital humps or superhumps.
 If you have BVR filters and a large enough aperture to get a
SNR of 30 please get as much data as possible. Time resolution
is not a priority so feel free to take long exposures and
stack. Have your filters ready and monitor the aavso-discussion
and aavso-photometry mailing lists for announcements of a
rebrightening. It won't last long so get on quickly. If you are
available, go ahead and observe it filtered while in
quiescence. An extra bonus would be to get filtered
observations of the object as it begins the outburst!
  Observe unfiltered if you don't have filters or if your
aperture doesn't support filtered observations of faint
objects.
  Reminders: 1. Make sure your computer's clock is sync'd. 2.
Watch out for the companion to the east in your photometry. 3.
if the Moon poses a significant problem see if R band
photometry reduces interference. (Let us know if it helps.)


Clear skies,

Aaron Price, Technical Assistant
on behalf of Elizabeth Waagen, Interim Director