J/A+A/603/A72 R light curves of MN Dra (Bakowska+, 2017)
MN Draconis: a peculiar, active dwarf nova in the period gap.
Bakowska K., Olech A., Pospieszynski R., Swierczynski E., Martinelli F.,
Rutkowski A., Koff R., Drozd K., Butkiewicz-Bak M., Kankiewicz P.
<Astron. Astrophys. 603, A72 (2017)>
=2017A&A...603A..72B 2017A&A...603A..72B (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, cataclysmic ; Novae ; Photometry
Keywords: binaries (including multiple): close -
stars: individual: MN Draconis - novae, cataclysmic variables -
stars: dwarf novae
Abstract:
We present results of an extensive world-wide observing campaign of MN
Draconis.
MN Draconis is a poorly known active dwarf nova in the period gap and
is one of the only two known cases of period gap SU UMa objects
showing the negative superhumps. Photometric behaviour of MN Draconis
poses a challenge for existing models of the superhump and
superoutburst mechanisms. Therefore, thorough investigation of
peculiar systems, such as MN Draconis, is crucial for our
understanding of evolution of the close binary stars.
To measure fundamental parameters of the system, we collected
photometric data in October 2009, June-September 2013 and
June-December 2015. Analysis of the light curves, O-C diagrams and
power spectra was carried out.
During our three observational seasons we detected four superoutburts
and several normal outbursts. Based on the two consecutive
superoutbursts detected in 2015, the supercycle length was derived
Psc=74±0.5-days and it has been increasing with a rate of
Pdot=3.3x10-3 during last twelve years. Based on the positive and
negative superhumps we calculated the period excess
ε=5.6%±0.1%, the period deficit ε_=2.5%±0.6%, and
in result, the orbital period Porb=0.0994(1)days
(143.126±0.144min). We updated the basic light curve parameters of
MN Draconis.
MN Draconis is the first discovered SU UMa system in the period gap
with increasing supercycle length.
Description:
The observational data of MN Dra presented here were collected
throughout three observation campaigns. The first data were obtained
during 6 nights from 2009 October 12 to October 22, in the Skinakas
Observatory, Greece. At that time, the star was in a quiescent state.
The second campaign was conducted during 15 nights from 2013 July 09
to September 10. On that occasion, data were gathered in Poland, at
the Borowiec station of the Poznan Astronomical Observatory, at J.
Kochanowski University in Kielce, and at the Ostrowik station of
theWarsaw University Observatory. During the 2013 campaign we detected
two superoutbursts of MN Dra. The longest campaign was organized in
2015, from June 4 to December 18. Data covering 84 nights of
observations were collected at the Borowiec Station, in Pisa in Italy,
at Antelope Hills Observatory and at the MDM Observatory in the USA.
Once again, two superoutbursts inMN Dra were observed.
R broad-band photometry of MN Dra was obtained in three runs organized
in 2009 (table 2009.dat), 2013 (table 2013.dat) and 2015 (table
2015.dat).
Objects:
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RA (2000) DE Designation(s)
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20 23 38.146 +64 36 27.19 MN Dra = V73 Dra
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
2009.dat 31 371 R photometry of MN Dra from 2009
2013.dat 35 2564 R photometry of MN Dra from 2013
2015.dat 35 5187 R photometry of MN Dra from 2015
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Byte-by-byte Description of file: 2009.dat 2013.dat 2015.dat
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Bytes Format Units Label Explanations
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1- 16 F16.8 d HJD Helicentric Julian Date
18- 24 F7.4 mag Rmag R magnitude
26- 35 F10.8 mag e_Rmag rms uncertainty on Rmag
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Acknowledgements:
Karolina Bakowska, bakowska(at)camk.edu.pl
(End) Patricia Vannier [CDS] 27-Mar-2017