[vsnet-obs 37489] CCD observations, late Dec 2001

["Berto Monard" <LAGMonar@csir.co.za>]

Hi,

During initial trials to master CCD observations I made some short
duration observations of relatively faint variables, mainly cataclysmic
systems. Improved alignment and stacking techniques will in future allow
longer exposures and fainter magnitudes. It is my intention to regularly
monitor those variables in future, weather and time allowing. They will
be done as a run up to an evening/night of timeseries, just long enough
for the focus conditions to be reasonably stabilised, if that is
possible. 

I have used the CR magnitude symbol in the results. They are not the
image reduction software read-outs. 
The following procedure was followed.
The CCD images were conditioned for background and flatfieldied. Using
data and information from UCAC1 and USNO-A2.0, R sequences were derived
for the measured starfields. Brightness measurements from the image
processing software were used to compare the magnitudes of the variables
by comparison to the R sequence. Since the effective wavelength of the
unfiltered CCD system is close to that of the R band, the derived CR
values are close to R. 
Since most of the measured targets are cataclysmic systems, the CR or R
magnitudes are very close to those for V (and even B). This applies
especially to the measurements of polars, possibly DQ Her stars, NLs,
CNe and most SNe. Slow accreting CVs will show more of the the reddish
spectrum originating from the secondary star and this to different
extents, at least that is what I speculate..

It was amazing to see how well the sequence derived values agreed with
those directly given via aperture photometry by the imaging software (ie
in most cases!).

I like to believe that here might be interest in these observations, if
not I'll keep future ones to myself :)) 


CCD observations of 22-29 December 2001 
observer: Berto Monard  MLF, Pretoria, South Africa
location: -25 º 54' 48", 28º 26' 44"E
instrumentation: LX200 12" f/5 with ST-7E
conditions: divers
 
HYIBL   011228.790   163CR   MLF
RXSJ0230-6842   011228.795   164CR   MLF
ERIEF   011222.822   179CR   MLF
RXSJ0354-1652   011222.825   174CR   MLF
RXSJ0425-1945   011222.83   <180CR   MLF  
PICTW   011228.981   147CR   MLF
PICUW   011222.84   159CR   MLF
PICUW   011228.983   156CR   MLF
PUPVV   011228.966   165CR   MLF
PYXWX   011228.969   163CR   MLF
PUPV615   011228.99   <170CR   MLF
CARV436   011228.988   150CR   MLF
MUSGU   011229.0   <175CR   MLF
CENV1033   011229.00   <170CR   MLF
CENV834   011229.021   175CR   MLF
CENV1025   011229.02   170CR   MLF
RXJ1313.2-3259   011229.020   154CR   MLF
CE-315   011229.076   180CR   MLF
CENV822   011229.08   <170CR   MLF
CENV895   011229.080   167CR   MLF
4U1543-62   011229.084   152CR   MLF
J1628-41   011229.094   134CR   MLF   (remarkable R mag..)
SCOV1033   011229.10   <160CR   MLF
ARAV877   011229.088   171CR   MLF

SN2001el   011222.81   157CR   MLF
SN2001el   011228.779   160CR   MLF
SN2001ig   011222.76   127CR   MLF
SN2001ig   011228.757   124CR   MLF

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