\documentstyle[twoside]{article}

\input ibvs2.sty
\input ibvse.sty

\begin{document}
\IBVShead{5224}{21 January 2002}

\IBVStitle{Minima of binary stars}

\IBVSauth{Nelson, Robert H.}

\IBVSinsto{College of New Caledonia, 3330 - 22nd Avenue, Prince
George, BC, Canada, V2N 1P8 \\e-mail: nelson@cnc.bc.ca}

\IBVStyp{ Binaries: eclipsing }

\begintext

\IBVSEobs{Prince George Astronomical Observatory (PGAO):  61 cm f/12 Cassegrain;
Backyard Observatory (BYO):  33 cm f/4.5 Newtonian on Paramount GT-1100s mount} 

\IBVSEdet{PGAO:  SBIG ST6 with telecompressor (to f/7), 
1\farcs1 $\times$ 1\farcs3 pixels, 5\arcm $\,\times$ 7\arcm FOV, cooled to $-$40 \deg{C}
BYO:  SBIG ST9e with tele-extender (to f/8.9), 1\farcs4 pixels,  
11\farcm9 $\times$ 11\farcm9 FOV, cooled to $-$10 \deg{C}}

\IBVSEred{Aperture photometry using MIRA, by Axiom Research}

\IBVSEmethod{Digital tracing paper method, bisection of chords, curve fitting, 
and Kwee and van Woerden (1956)}

{\small
\IBVSEstars{CX Aqr & EA/SD & 22.3544 & $-$0.4126 & G 5233:1831 & 52136.8117 & 0.555986  & 1. \\
HP Aur & EA & 5.10216 & 35.4748 & [not GSC] & 51936.3787 & 1.422819  & 1. \\
TY Boo & EW/KW & 15.0047 & 35.0752 & G 2568:0991 & 51957.8764 & 0.317150  & 1. \\
CV Boo & na & 15.26192 & 36.5915 & G 2570:0423 & 51955.9444 & 0.846994  & 1. \\
AE Cas & EA/SD & 1.26573 & 70.0733 & G 4301:1549 & 51947.3320 & 0.759121  & 1. \\
PV Cas & EA/DM & 23.10025 & 59.1206 & G 4010:1111 & 52135.8214 & 1.750454  & 1. \\
V387 Cas & EA/DM & 1.00355 & 58.4157 & G 3680:1741 & 52133.8565 & 1.608211  & 1. \\
XX Cep & EA/SD & 23.38199 & 64.2 & G 4288:0150 & 52136.9064 & 2.337306  & 1. \\
XY Cep & EA/SD & 23.535637 & 68.5823 & G 4479:0423 & 51931.7501 & 2.774517  & 1. \\
GW Cep & EW/KW & 1.45591 & 80.0456 & G 4502:0724 & 51957.9425 & 0.318844  & 1. \\
XZ CMi & EA & 7.54065 & 3.3854 & G 0185:1509 & 51936.8652 & 0.578807  & 1. \\
AK CMi & EA/SD & 4.37064 & 1.4023 & G 0187:1081 & 51913.8210 & 2.043367  & 1. \\
EK Com & EW & 12.5121 & 27.1347 & G 1995:2289 & 51961.0457 & 0.266686  & 1. \\
V859 Cyg & EW/KW & 19.27124 & 28.565 & G 2137:0260 & 49580.3946 & 0.405004  & 1. \\
}
}

{\small
\IBVSEstars{ AF Gem & EA/SD & 6.50343 & 21.2233 & G 1343:2551 & 51922.8889 & 1.243499  & 1. \\
V728 Her & EW/KW & 17.1805 & 41.5041 & G 3081:1028 & 51676.8628 & 0.471286  & 1. \\
WY Hya & EW/KE & 8.14112 & 0.302 & G 0195:1434 & 51964.8064 & 0.716008  & 1. \\
AV Hya & EB/KE & 9.35025 & 5.1911 & G 0241:2130 & 51961.7943 & 0.683400  & 1. \\
DF Hya & EW/KW & 8.5223 & 6.1736 & G 0225:0943 & 51934.9513 & 0.330597  & 1. \\
CN Lac & EB/DW & 0.20305 & 40.1335 & G 3605-2646 & 51812.8787 & 0.462790  & 1. \\
DU Leo & na & 9.4411 & 25.2115 & G 2568:0991 & 52013.6090 & 0.687093  & 1. \\
NS Mon & EW/DW & 6.3326 & 7.5418 & G 0733:2002 & 51933.7458 & 1.777619  & 1. \\
BB Peg & EW/KW & 22.22556 & 16.1959 & G 1682:1530 & 52132.0233 & 0.361502  & 1. \\
BX Peg & EW/KW & 21.38532 & 26.4223 & G 2197:1485 & 51761.9154 & 0.280417  & 1. \\
DV Peg & EW/KE & 21.2452 & 21.1 & G 1675:0092 & 52112.8601 & 0.949625  & 1. \\
DK Peg & EA/DM & 23.41335 & 10.1257 & G 1173:1705 & 52132.8317 & 1.631827  & 1. \\
KL Per & EA/SD & 2.41167 & 48.5618 & G 3304:0460 & 51166.3595 & 2.223015  & 1. \\
Y Psc & EA/SD & 23.34253 & 7.5529 & G 1169:0263 & 52134.9441 & 3.765759  & 1. \\
AU Ser & EW/KW & 15.56492 & 22.154 & G 1502:1573 & 52028.8138 & 0.386494  & 1. \\
AC Tau & EA/SD & 4.37064 & 1.4023 & G 0082:0234 & 51913.8210 & 2.043367  & 1. \\
RV Tri & EA/SD & 2.1318 & 37.0101 & G 2321:0244 & 52116.8846 & 0.753666  & 1. \\
AX Vir & EB/KE & 13.2745 & 3.5228 & G 0303:0193 & 51964.9697 & 0.702526  & 1. \\
G1534:0753 & na & 17.025047 & 21.3959 & G 1534:1027 & 52015.0936 & 0.511158  & 1. \\
G1991:1390 & na & 12.32049 & 26.2248 & G 1991:1447 & 51992.8346 & 0.286362  & 1. \\
G1991:1390 & na & 12.32049 & 26.2248 & G 1991:1447 & 51992.8346 & 0.286362  & 1. \\
G2035:0175 & na & 16.0154 & 24.5216 & G 2035:0109 & 51750.7083 & 0.268730  & 1. \\
G2035:0175 & na & 16.0154 & 24.5216 & G 2035:0109 & 51750.7083 & 0.268730  & 1. \\
G2038:0674 & na & 16.1005 & 25.3655 & G 2038:0040 & 51989.9672 & 0.530831  & 1. \\
G2530:2276 & na & 12.3201 & 35.29597 & G 2530:2154 & 51991.9728 & 0.305967  & 1. \\
G2532:0514 & na & 13.00117 & 30.231 & G 2532:0946 & 52010.7820 & 0.301988  & 1. \\
G2532:0514 & na & 13.00117 & 30.231 & G 2532:0946 & 52010.7820 & 0.301988  & 1. \\
G2533:1519 & na & 12.4033 & 34.2256 & G 2533:1553 & 51998.7445 & 0.491419  & 1. \\
G2533:1563 & na & 12.4441 & 35.5756 & G 2533:0959 & 51956.0078 & 0.329068  & 1. \\
G3021:2642 & na & 12.4337 & 38.4415 & G 3021:2615 & 51955.7666 & 0.326894  & 1. \\
G3021:2642 & na & 12.4337 & 38.4415 & G 3021:2613 & 51955.7666 & 0.326894  & 1. \\
G3026:1046 & na & 13.3726 & 37.3458 & G 3026:0922 & 52001.9066 & 0.349189  & 1. \\
G3092:1291 & na & 17.4411 & 40.1655 & G 3092:1157 & 52024.9883 & 0.346925  & 1. \\
G3103:0919 & na & 18.1521 & 39.0545 & G 3103:0849 & 52064.8900 & 1.238813  & 1. \\
G3112:0179 & na & 18.2138 & 42.1008 & G 3112:1051 & 52054.8478 & 0.995959  & 1. \\
}  
}

Notes:  RA values are in the format HH.MMSS, Dec in DD.MMSS.
\break G stands for GSC.

\IBVSEsource{1. This paper (see remarks).}

\IBVSEremexp{* Note: The comparison for HP Aur is located approximately 
1\deg\,north of the variable.}


\IBVSEmin{ CX Aqr & 52136.8123 & 0.0002 & I & none &  &BYO \\
HP Aur * & 51935.6673 & 0.0001 & II & none &  &PGAO \\
TY Boo & 51957.8764 & 0.0001 & I & none &  &PGAO \\
CV Boo & 51955.9444 & 0.0001 & I & none &  &PGAO \\
AE Cas & 51913.9283 & 0.0001 & I & none &  &PGAO \\
AE Cas & 51946.9520 & 0.001 & II & none &  &PGAO \\
PV Cas & 52135.8214 & 0.0001 & I & none &  &BYO \\
V387 Cas & 52133.8565 & 0.0004 & I & none &  &BYO \\
XX Cep & 52136.9064 & 0.0004 & I & none &  &BYO \\
XY Cep & 51931.7501 & 0.0005 & I & none &  &PGAO \\
GW Cep & 51935.7847 & 0.0001 & II & none &  &PGAO \\
GW Cep & 51957.7830 & 0.0001 & II & none &  &PGAO \\
XZ CMi & 51936.8652 & 0.0002 & I & none &  &PGAO \\
AK CMi & 51934.7501 & 0.0003 & I & none &  &PGAO \\
EK Com & 51960.9124 & 0.0002 & II & none &  &PGAO \\
V859 Cyg & 52134.7548 & 0.0001 & I & none &  &BYO \\
AF Gem & 51922.8889 & 0.0002 & I & none &  &PGAO \\
V728 Her & 51983.9129 & 0.0002 & II & none &  &BYO \\
WY Hya & 51916.8334 & 0.0001 & I & none &  &PGAO \\
WY Hya & 51964.8064 & 0.0002 & I & none &  &PGAO \\
AV Hya & 51961.7943 & 0.0002 & I & none &  &PGAO \\
DF Hya & 51934.9513 & 0.0001 & II & none &  &PGAO \\
CN Lac & 52093.8300 & 0.001 & I & none &  &BYO \\
DU Leo & 51957.9543 & 0.0002 & II & none &  &PGAO \\
NS Mon & 51933.7458 & 0.0002 & I & none &  &PGAO \\
BB Peg & 52131.8425 & 0.0002 & II & none &  &BYO \\
BX Peg & 52015.9750 & 0.0001 & I & none &  &BYO \\
DV Peg & 52112.8601 & 0.0002 & II & none &  &BYO \\
DK Peg & 52132.8317 & 0.0001 & I & none &  &BYO \\
KL Per & 52137.8501 & 0.0007 & I & none &  &BYO \\
Y Psc & 52134.9441 & 0.0002 & I & none &  &BYO \\
AU Ser & 52028.8139 & 0.0001 & I & none &  &BYO \\
AC Tau & 51913.8210 & 0.0001 & I & none &  &PGAO \\
RV Tri & 52116.8845 & 0.0001 & I & none &  &BYO \\
AX Vir & 51964.9697 & 0.0002 & I & none &  &PGAO \\
G1534:0753 & 52014.8379 & 0.0001 & II & none &  &BYO \\
G1991:1390 & 51992.8346 & 0.0001 & I & none &  &PGAO \\
G1991:1390 & 51962.9098 & 0.0001 & II & none &  &PGAO \\
G2035:0175 & 52019.8715 & 0.0001 & I & none &  &BYO \\
G2035:0175 & 52038.8169 & 0.0001 & II & none &  &BYO \\
G2038:0674 & 51989.8345 & 0.0001 & II? & none &  & BYO \\
G2530:2276 & 51991.8204 & 0.0002 & II & none &  &BYO \\
G2532:0514 & 52010.7820 & 0.0002 & I & none &  &BYO \\
G2532:0514 & 52000.8160 & 0.0001 & I & none &  &BYO \\
G2533:1519 & 51998.7440 & 0.0002 & I & none &  &BYO \\
G2533:1563 & 51955.8433 & 0.0003 & II? & none &  & PGAO \\
}

\IBVSEmin{G3021:2642 & 51955.7666 & 0.0002 & II & none &  &PGAO \\
G3021:2642 & 52014.7711 & 0.0002 & I & none &  &BYO \\
G3026:1046 & 52001.7327 & 0.0002 & I & none &  &BYO \\
G3092:1291 & 52024.8148 & 0.0001 & I & none &  &BYO \\
G3103:0919 & 52064.8900 & 0.01 & I & none &  &BYO \\
G3112:0179 & 52054.8499 & 0.0007 & I & none &  &BYO \\
}

\IBVSErem{A problem emerged for the BYO data during the routine photometry of 
the check stars, performed some time after the original data were taken and 
reduced.  It was discovered that nightly drifts of a few hundreds of a 
magnitude occurred for the check stars in some (but not all) data sets.  The 
causes of this drift are presently unknown (flatfielding was scrupulously done 
in all cases) but are thought to arise from possible misalignments of the 
tele-extender lens axis with that of the main optical axis, focussing errors, 
possibly inadequate tube baffling, stray lights, etc.  Clearly this situation 
is unacceptable and will be dealt with before more data are taken.
    However, to correct the existing BYO data, linear fits by least-squares 
were made of the check star magnitudes versus time and linear corrections 
(extrapolated to the location of the variable where possible) were applied to 
the variable star magnitudes versus time.  The times of minima were then 
redetermined and the differences from the uncorrected ToMs noted.  These 
differences, or corrections, ranged from 0.00008 to 0.01 days; the median was 
0.0004 days.
   Rather than discard some of the obviously less accurate times of minima, 
since many are for ROTSE stars (Akerlof, C., et al., 2000)  which have not been 
previously observed, it was decided to report all the values with estimated 
errors equal to the internally estimated errors or the corrections themselves, 
whichever was larger.  These are given in Table 2.
   Information on period behaviour for most of the stars listed in Table 1 is 
available in a website, the URL for which is given in the references.
The ephemerides were calculated with the help of O$-$C charts using all available published times of minima.
}

\IBVSEack{Thanks are due to Environment Canada for the website satellite views (see 
reference below) that were essential in predicting clear times for observing 
runs in this cloudy locale.
  The author is also a Guest User of the Canadian Astronomy Data Centre, which 
is operated by the Dominion Astrophysical Observatory for the National Research 
Council of Canada's Herzberg Institute of Astrophysics. }

\references

Akerlof, C., et al., 2000, AJ, 119, 1901 % \BIBCODE{2000AJ....119.1901A}

Kwee, K.K., \& van Woerden, H., 1956, B.A.N. 12, (464), 327-330

Nelson, R.H., 2000, IBVS, 4840

{\tt http://www.cmc.ec.gc.ca/cmc/htmls/satellite.html }

{\tt http://www.cnc.bc.ca/physics/Downloads/ }

\endreferences

\end{document}


