[Aavso-photometry] Var Her 04 - further analysis of CBA observations

[Tonny Vanmunster]

Dear colleagues,

Two further messages regarding Var Her 04 :

- I obtained unfiltered CCD photometric observations of Var Her 04 at CBA
Belgium Observatory, using a 0.35-m f/6.3 telescope and ST7XME CCD, on Jul
03/04 and on Jul 05/06, 2004. During the first night, the variable was
fluctuating around mag 15.2 (unfiltered), showing a modulation of about 0.2
mag. No dimming or rebrightening trend was visible. On the second night, the
variable initially was around mag 15.4 (unfiltered), but then showed a
sudden fading by 0.15 mag over a very short period. The variable then
remained 'steady' around mag 15.6 - 15.7. Light curves are published at
www.cbabelgium.com. I also tried a period analysis on the above datasets,
but no conclusive results were obtained.

Skies are clear over Belgium at this moment, and I started an observing
session on Var Her 04 around 22h UT (Jul 06/07, 2004). The object still is
faint (no trace of a rebrightening), and requires exposure times of 180s
with my setup.

- An additional 1695 CBA observations were obtained between JD 2453186 (Jun
29) and JD 2453193 (Jul 06), by Donn Starkey, David Messier, Brian Martin
and Tonny Vanmunster (this brings the total CBA observations to 4277, with
more data sets pending processing). At JD +3186, superhumps still were
clearly present, with a full amplitude near 0.2 mag. Around JD +3189, they
disappear from the light curve, but one night later a modulation of about
0.2 mag again reappears. The corresponding zero-averaged light curve is
visible at www.cbabelgium.com. A period analysis on the afore mentioned
segment of the light curve yields a period of 0.05748 +/- 0.00024 d, using
the ANOVA method (in Peranso), with intricate fine structure in the
harmonics. A second peak near 0.0612d is also present in the ANOVA period
window (published on my web site).

I'm not sure what to expect next from Var Her 04. Will it rebrighten or
continue to fade gradually ? Whatever it does, this object should remain a
top priority target.


Best regards,
Tonny


Tonny Vanmunster
CBA Belgium Observatory
http://www.cbabelgium.com
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PERANSO : The Final Frontier of Period Analysis Software
http://www.peranso.com
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