[Aavso-photometry] Re: [cvnet-discussion] VV is one lonely Pup!

[Berto Monard]

Dear Aaron,

Recent 'unfiltered' observations show VV pup evolving around 17.5CR. I
wonder if, at this faint level, any precise timeseries photometry via
filtered observations can be done by the usual amateur instrumentation.


But if VV Pup is a polar, it will give a reasonably good signal over
the unfiltered CCD band while measurements in the different bands will
likely show a similar light curve. 

At decl -19, VV Pup is very much equatorial, which means that longer
exposures (more than 30 sec) will produce significant star trailing on
most of the images with the commercal type telescopes. This will firmly
reduce the magnitude reach in filtered photometry.

If someone were (in addition to unfiltered runs, produced by others
perhaps) to make (by means of stackings) 'deep' snapshot observations in
the different filters, the overall information can still be had. From
past experience I am not a strong believer in the quality of timeseries
derived from stacked images...

I hope that Arne (in his capacity as expert astro-photometrist) has
comments on all this.

Good luck with the campaign. I will definitely apply a dense coverage
with snapshot observations, probably even with filters, weather
allowing.

Regards,

Berto Monard / #MLF

Bronberg Observatory / CBA Pretoria
   

>>> aaronp at onceler.org 10/02/2005 21:47:56 >>>

 Hey all. We really need CCD observations of VV Pup during the next
week. If you can observe it please make it your #1 priority target. We
have no recent data at all. Below is a copy/paste from the recent
announcement in CCD Views #330:

http://www.aavso.org/publications/ccdviews/330.shtml 
	  	
---------------------------------------------------------------------------
3. VV PUP CAMPAIGN IN SUPPORT OF KECK OBSERVATIONS
Dr. Steve Howell, WIYN Observatory & NOAO, has requested observations
of the polar VV Pup to coincide with observations being done at the
Keck Observatory on February 16, 2005 (UT). Time series observations
for as long as possible in BVRI are requested from 00:00 UT February
15 - 23:00 UT February 17, 2005. VV Pup is quite faint and also near
the quarter Moon during the observing window. So we recommend the
following observing plan:

1) Observe it in one filter instead of alternating between filters.
Set your exposure time to get an SNR > 20. You may need to stack
images to reach this SNR.

2) Small and moderately sized telescopes should observe in Ic first
and in Rc if you don't have an Ic filter or someone else is currently
observing in Ic. This will lessen some of the effects of the Moon and
also lower exposure time (this is a field with heavy extinction).
Those with larger apertures should go for V and B photometry.

3) Post to the aavso-photometry discussion group and tell us what
filter you are using and the expected start and end time of your
observation run. This way someone else can use a different filter if
they are observing at the same time.

We currently have very few observations of VV Pup. So baseline
observations prior to and immediately after the observing campaign
would be very useful.

The AAVSO Chat Room will be open for this event! Join us during the
campaign at http://www.aavso.org/aavso/chat.shtml .

The VV Pup chart is here:
http://www.aavso.org/cgi-bin/searchcharts3.pl?name=vv%20pup 

Our observations of VV Pup are minuscule!! We desperately need some
photometry. Our latest observations of VV Pup:
VV PUP JAN 01.4960 <15.3 SRX Visual
VV PUP DEC 31.8280 17.2 CCD MLF Unfiltered
VV PUP DEC 28.4424 16.305 CCDI CTX ERR: .03
VV PUP DEC 23.4785 18.38 CCDV CTX ERR: .027
SRX - Rod Stubbing, Australia
CTX - Tim Crawford, Oregon, USA
MLF - Berto Monard, South Africa 
-------------------------------------------------------------------------
Aaron


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