J/AJ/153/238 Mid-eclipse times of DV UMa (Han+, 2017)
Cyclic period oscillation of the eclipsing dwarf nova DV UMa.
Han Z.-T, Qian S.-B, Irina V., Zhu L.-Y
<Astron. J., 153, 238-238 (2017)>
=2017AJ....153..238H 2017AJ....153..238H (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing
Keywords: binaries: close - binaries: eclipsing - stars: dwarf novae -
stars: individual: DV UMa
Abstract:
DV UMa is an eclipsing dwarf nova with an orbital period of ∼2.06hr,
which lies just at the bottom edge of the period gap. To detect its
orbital period changes, we present 12 new mid-eclipse times by using
our CCD photometric data and archival data. The latest version of the
O-C diagram, combined with the published mid-eclipse times in
quiescence, and spanning ∼30 years, was obtained and analyzed. The
best fit to those available eclipse timings shows that the orbital
period of DV UMa is undergoing a cyclic oscillation with a period of
17.58(±0.52) years and an amplitude of 71.1(±6.7) s. The periodic
variation most likely arises from the light-travel-time effect via the
presence of a circumbinary object, because the required energy to
drive the Applegate mechanism is too high in this system. The mass of
the unseen companion was derived as M3sini'=0.025(±0.004)M☉.
If the third body is in the orbital plane (i.e., i'=i=82.9°) of
the eclipsing pair, this would indicate it is a brown dwarf. This
hypothetical brown dwarf is orbiting its host star at a separation of
∼8.6 au in an eccentric orbit (e=0.44).
Description:
New CCD photometric observations of DV UMa were carried out by using
three different telescopes. Beginning on 2009 November 12, this star
was continuously monitored with the 2.4m telescope at the Lijiang
observational station of Yunnan Observatories (YNAO). To collect more
data for this binary, an observation was made on 2016 March 29 with an
Andor DW436 1K CCD camera mounted on the 85cm reflecting telescope at
the XingLong station of the National Astronomical Observatory and
another observation made on 2017 January 23 with an Andor DW936 2K CCD
camera attached to the 1.0m reflecting telescope at YNAO. During the
observations, no filters were used in order to improve the time
resolution.
Objects:
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RA (ICRS) DE Designation(s)
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09 46 36.65 +44 46 45.1 V* DV UMa = US 943
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 56 112 All mid-eclipse times of DV UMa
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date of minimum light
15- 20 I6 --- E [1/127225] Epoch number
22- 30 F9.6 d O-C The (O-C) residual
32- 38 F7.5 d e_O-C Error in O-C
40- 49 A10 --- State State (outburst or quiescence)
51- 54 A4 --- Tel Telescope (1.0m, 2.4m, 85cm)
56 I1 --- Ref Reference (1)
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Note (1): Reference codes are defined as follows:
1 = Howell et al. (1988MNRAS.233...79H 1988MNRAS.233...79H);
2 = Nogami et al. (2001MNRAS.322...79N 2001MNRAS.322...79N);
3 = Patterson et al. (2000PASP..112.1584P 2000PASP..112.1584P);
4 = Feline et al. (2004MNRAS.355....1F 2004MNRAS.355....1F);
5 = American Association of Variable Star Observers (AAVSO) data;
6 = Our observations.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 10-Aug-2017