Download Snímka 1

KOLOS
Our team:
Ladislav Hric
Astronomical Institute
Slovak Academy of Sciences
V. Breus
P. Dubovský
R. Gális
N. A. Katysheva
E. Kundra
S. Yu. Shugarov
Schematic picture of CV – non magnetic system
Schematic picture of CV – the strong magnetic
system - Polar
Schematic picture of CV – the moderately
magnetic system - intermediate polar
V709 Cas was discovered as an optical
counterpart of the ROSAT source RX J0028.8+5917 by
Haberl & Motch (1995)
The soft X-Ray flux was changing
with a period of 312.8 s, which is the spin
period of the white dwarf
Radial velocity variations showed
2 possible orbital periods P = 5.4 h and 4.45 h
which are one day aliases of each other (Motch 1996)
Note to spin and orbital periods, the reprocessing of X-rays at some
part of the system that revolves at the binary period gives rise to
emission that varies with the beat period, where
1/Pbeat = 1/Pspin − 1/Porbit
This synodic counterpart is often called the orbital sideband of the
spin frequency.
Kozhevnikov (2001) reported the
presence of strong optical oscillations at the
spin period of 312.77 s and it’s orbital sideband of 317.94 s.
Bonnet-Bidaud et al. (2001) studied radial velocities
of the emission lines and published the ephemeris
T0 = HJD 2451048.0575(2) + 0.2225(2) x E.
Tamburini et al. (2009) studied the white-light flickering
and reported that the light curve is strongly flickering dominated
without any dominating frequency except the orbital motion.
Thorstensen et al. (2010) found the value of the orbital
period of the system using radial velocity spectroscopy
P= 0d.2222033(7) .
We obtained photometric CCD observations using different
telescopes:
50cm AZT-5 (13 nights),
60cm Zeiss-Cassegrain (2 nights),
38cm K-380 (19 nights) at the Crimean Astrophysical Observatory
(CrAO), and Crimean Laboratory of Sternberg Astronomical Institute,
Nauchny, Crimea, Ukraine,
and
1m Vihorlat National Telescope
(VNT) (22 nights),
Celestron 14 (1 night)
at the Kolonica Observatory (KO), Slovakia mainly in V and R filters.
10 years of observations
Periodograms near frequrency, that corresponds to the
spin period of the white dwarf, exhibit the different
highest peaks for different nights of observations in the
range from 185 s to 330 s.
Particulary, for data obtained 7. Oct 2010
at the 1m VNT we got highest peak that corresponds to
the spin period of 311.7(4) s.
Period analysis
Results
Using all determined minima timings, we
calculated (O - C) diagram with initial values
of period P = 0.2222041 d (Thorstensen et al.
2010) and initial epoch T0 = 2454028.43349
determined for one night from the middle of
our data.
We chose the linear
fit as the best
approximation for
the (O - C) data and
the resulting orbital
period was Porb =
0.2222123(6) d.
Results
Results
The new period
Periodograms in the range of 0.002 - 0.02 days exhibit strong peak around
the period of 23 minutes (0.016 d). Different nights show different highest
peaks in the range from 0.010 d to 0.019 d.
We took the average value of Pnew = 0.01645 d, which corresponds to the
frequency of 60.79 /day in the periodograms.
Finally we took the set of 3 nights.
The period analysis of these data
reveals the highest peak at the
frequency
f = 61.15 /day which corresponds to
the newly detected period of
Pnew = 0.0163510(3) d.
Periodogram
The new period
The new period
What about the conclusion
It is worth to note that on the published by Norton (1999) and
Kozhevnikov (2001) power spectra it is possible to identify the peaks
corresponding to our new period. In the paper by Kozhevnikov (2001) the
peak is more than two times higher than the spin period. Both authors did
not notice this fact in their papers.
These evidences support our
opinion,
that
the
period
discovered by us is caused by real
physical process. One of the
possible explanations is the
vibration of the accretion stream
in the magnetic field of the white
dwarf.
The explanation of this new
period is only speculative and for
better understanding it is
necessary to get spectroscopic
data with higher time resolution.
Our paper
The new data
Photometry of V709 Cas in Stará Lesná and Hlohovec Observatories
Date [m/d/year]
START
END
10/1/2007 20:20
10/6/2007 19:35
10/7/2007 22:10
12/27/2007 16:43
2/25/2008 18:10
2/26/2008 17:37
10/28/2009 21:32
11/9/2009 17:32
11/18/2009 16:08
11/19/2009 16:34
11/21/2009 18:52
12/3/2009 16:43
12/4/2009 16:52
12/20/2009 16:20
12/21/2009 16:12
1/4/2010 17:15
2/4/2010 16:41
10/7/2010 18:53
10/8/2010 19:19
1/28/2011 16:45
2/2/2011 17:13
9/6/2011 18:56
11/18/2013 19:06
12/2/2013 23:47
2/3/2014 19:25
2/13/2014 20:20
2/24/2014 17:58
10/25/2014 18:00
11/3/2014 21:00
6/14/2014 20:27
6/21/2014 21:01
10/1/2007 23:46
10/7/2007 0:20
10/8/2007 0:07
12/27/2007 20:25
2/25/2008 20:12
2/26/2008 20:16
10/28/2009 23:58
11/9/2009 17:59
11/18/2009 21:16
11/20/2009 4:39
11/22/2009 4:47
12/4/2009 4:26
12/4/2009 23:22
12/20/2009 22:50
12/21/2009 18:07
1/4/2010 21:50
2/4/2010 20:47
10/8/2010 3:30
10/9/2010 2:16
1/28/2011 17:34
2/2/2011 19:36
9/7/2011 2:33
11/18/2013 19:14
12/3/2013 2:20
2/3/2014 20:36
2/13/2014 21:20
2/24/2014 20:20
10/25/2014 19:00
11/3/2014 22:00
6/14/2014 21:42
6/21/2014 21:53
JD/MJD
START
END
54375.34744
54380.31656
54381.42378
54462.19669
54522.25721
54523.23461
55133.39773
55145.23060
55154.17291
55155.19044
55157.28661
55169.19676
55170.20322
55186.18124
55187.17534
55201.21928
55232.19547
55477.28700
55478.30527
55590.19793
55595.21781
55811.28904
56615.29622
56629.49127
56692.30963
56702.34266
56713.24926
56956.25515
56965.40890
56823.35260
56830.37600
54375.49080
54380.51449
54381.50519
54462.35101
54522.34174
54523.34494
55133.49916
55145.24947
55154.38612
55155.69428
55157.69979
55169.68536
55170.47389
55186.45174
55187.25538
55201.41034
55232.36597
55477.64631
55478.59472
55590.23244
55595.31713
55811.60678
56615.30177
56629.59748
56692.35897
56702.38841
56713.34747
56956.29022
56965.44661
56823.40466
56830.41193
Duration
[hours]
Filter
3.441
BVRI
4.750
BVRI
1.954
BVRI
3.704
BVRI
2.029
UBVRI
2.648
UBVRI
2.434
BVRI
0.453
BRI
5.117
BRI
12.092
BRI
9.916
BVRI
11.726
BVRI
6.496
BVRI
6.492
BVRI
1.921
BVRI
4.585
BVRI
4.092
BVRI
8.623
V
6.947
V
0.828
BVRI
2.384
BVRI
7.626
BVRI
0.133
BVRI Short!
2.549
V
1.184
VN
1.----N 67
2.357 VN long+BRI short
1.----V 92 B 5 R 9
1.----V 26 R 25 I 30
1.249
R
0.862
C
Instrument
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
508/2500 G1
G1_50cm_SBIG
G1_50cm_SBIG
G1 SBIG Dual Chip
G1_50cm_SBIG
G1_50cm_SBIG
G1_50cm_SBIG
G1_50cm_SBIG
G1_50cm_SBIG
G1_60cm_FLI2 Zeiss 600/7500
G1_60cm_FLI2
G1_60cm_FLI2
G2_60cm_MI G4-9000 CCD
G1_60cm_FLI2
G1_60cm_FLI ML3041 CCD
G2_60cm_MI G4-9000 CCD
Hlohovec, ZC600, SBIG ST-9
Hlohovec, ZC600, SBIG ST-9
The new data
The new data
Spectroscopy of V709 Cas at 6 m Telescope in SAO
Date
[yyyymmdd]
Sp. Resolution
20141030 5 Å or 15 000 – 17 000
Time resolution Duration
about 5 min
Telescope
2 – 3 hours BTA 6 m
Acknowledgements

Thank you
very much
for your
attention