BD +14°5016 - A NEW EW ECLIPSING BINARY
Maciejewski, G., Karska, A., Niedzielski, A.
December 3, 2002
BD +14°5016
was found to be variable during the Semi-Automatic
Variability Search program at the Piwnice Observatory. The presented
photometric data were collected in both B and V filters, during 16
moonless nights between September and November 2002. 334 individual
measurements of brightness were made, 275 in V band and 59 in B.
The shape of the phased light curve indicates variability of the W UMa type.
According to SIMBAD,
BD +14°5016
is a V=9.50 magnitude
star of F2 spectral type, with B-V=0.31 mag. Our observations show that at the maximum
light the star reaches mV=9.28 mag and mB=9.63 mag. The primary
and secondary minima have an amplitude of 0.47 mag and 0.41 mag respectively. The observed amplitudes in
B are identical. No noticeable colour variation with phase was
detected. The phase-averaged (mB-mV)=0.35. The maximum
following the second minimum is 0.04 mag fainter in both bands suggesting presence of a spot
placed on the surface of one of the components.
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The period was found with the ANOVA method. The
times of both minima were computed from the presented light-curve with the
Kwee-van Woerden method. A preliminary ephemeris for the
primary minimum is:
Min.I = HJD 2452558.1703(3) + 0.d636889(4) x E. [1]
The shape of the phased light curve clearly shows that the secondary
minimum is located at phase 0.52. This fact is confirmed by large O-C
values calculated from equation [1] for the observed secondary minima. Therefore
the following ephemeris for the secondary minimum has been obtained:
Min.II = HJD 2452557.8658(6) + 0.d636889(4) x E. [2]
To estimate accuracy of calculated minima the collected data were divided in
three sessions separated by full moon nights or a long period of bad weather conditions
and for each session individual times of minima were determined by the digital
tracing paper method. The O-C values, presented below, were calculated for
primary and secondary minima from equation [1] and [2] respectively.
| Min. HJD |
Error |
Type |
Filter |
O-C [day] |
| 2452534.2999 |
0.0014 |
II |
V |
-0.0010 |
| 2452534.6031 |
0.0008 |
I |
V |
-0.0016 |
| 2452552.7715 |
0.0013 |
II |
V |
+0.0008 |
| 2452553.073 |
0.003 |
I |
V |
-0.0024 |
| 2452582.706 |
0.002 |
II |
V |
+0.0014 |
| 2452583.007 |
0.002 |
I |
V |
-0.0014 |
| 2452583.3386 |
0.0032 |
II |
B |
-0.0028 |
| 2452583.6441 |
0.0011 |
I |
B |
-0.0018 |
The results were published in IBVS 5343 (compressed PostScript). The data are available upon request.
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