scholarly journals A Photometric Study of the Newly Discovered Eclipsing Cataclysmic Variable SDSS J040714.78–064425.1

2005 ◽  
Vol 22 (2) ◽  
pp. 105-110 ◽  
Author(s):  
T. Ak ◽  
A. Retter ◽  
A. Liu ◽  
H. H. Esenoğlu
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Cataclysmic Variable ◽  
Photometric Study ◽  
Dwarf Nova ◽  
Ccd Observations ◽  
Optical Light Curve ◽  
Orbital Periods

AbstractWe present the results obtained from unfiltered photometric CCD observations of the newly discovered cataclysmic variable SDSS J040714.78–064425.1 made during seven nights in 2003 November. We establish the dwarf nova nature of the object as it was in outburst during our observations. We also confirm the presence of deep eclipses with a period of 0.17017 ± 0.00003 d in the optical light curve of the star. In addition, we found periods of 0.166 ± 0.001 d and possibly also 5.3 ± 0.7 d in the data. The 0.17017 d periodicity is consistent within the errors with the proposed orbital period of 0.165 and 0.1700 d. Using the known relation between the orbital and superhump periods, we interpret the 0.166 and 5.3 d periods as the negative superhump and the nodal precession period respectively. SDSS J040714.78–064425.1 is then classified as a negative superhump system with one of the largest orbital periods.

scholarly journals Two bodies with high eccentricity around the cataclysmic variable QS Vir

2010 ◽  
Vol 6 (S276) ◽  
pp. 495-496 ◽  
Author(s):  
Leonardo A. Almeida ◽  
Francisco Jablonski
Keyword(s):  
Orbital Period ◽  
Giant Planet ◽  
Cataclysmic Variable ◽  
Brown Dwarf ◽  
Period Variations ◽  
Angular Momentum Loss ◽  
Best Fitting ◽  
Orbital Periods ◽  
The Masses ◽  
Two Bodies

AbstractQS Vir is an eclipsing cataclysmic variable with 3.618 hrs orbital period. This system has the interesting characteristics that it does not show mass transfer between the components through the L1 Lagrangian point and shows a complex orbital period variation history. Qian et al. (2010) associated the orbital period variations to the presence of a giant planet in the system plus angular momentum loss via magnetic braking. Parsons et al. (2010) obtained new eclipse timings and observed that the orbital period variations associated to a hypothetical giant planet disagree with their measurements and concluded that the decrease in orbital period is part of a cyclic variation with period ~16 yrs. In this work, we present 28 new eclipse timings of QS Vir and suggest that the orbital period variations can be explained by a model with two circumbinary bodies. The best fitting gives the lower limit to the masses M1 sin(i) ~ 0.0086 M⊙ and M2 sin(i) ~ 0.054 M⊙; orbital periods P1 ~ 14.4 yrs and P2 ~ 16.99 yrs, and eccentricities e1 ~ 0.62 and e2~0.92 for the two external bodies. Under the assumption of coplanarity among the two external bodies and the inner binary, we obtain a giant planet with ~0.009 M⊙ and a brown dwarf with ~ 0.056 M⊙ around the eclipsing binary QS Vir.

scholarly journals Characterising the Dwarf Nova Population of the Catalina Real-time Transient Survey

2011 ◽  
Vol 7 (S285) ◽  
pp. 301-302
Author(s):  
Deanne de Budè ◽  
Patrick Woudt ◽  
Brian Warner
Keyword(s):  
Real Time ◽  
Orbital Period ◽  
High Speed ◽  
Photometric Study ◽  
Dwarf Novae ◽  
Dwarf Nova

AbstractResults of a high-speed photometric study of dwarf novæ in the Catalina Real-time Transient Survey are given. A population of faint dwarf novæ near the orbital period minimum is detected. At the shortest periods there is a correlation between orbital period and outburst interval.

scholarly journals New Exosat Observations of TV Columbae: Preliminary Results

1987 ◽  
Vol 93 ◽  
pp. 261-267
Author(s):  
J. Schrijver ◽  
A.C. Brinkman ◽  
H. Van Der Woerd
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
White Dwarf ◽  
Lower Energy ◽  
Cataclysmic Variable ◽  
X Ray ◽  
Preliminary Results ◽  
First Results ◽  
Absorption Features ◽  
Energy Channels

AbstractThe first results of the analysis of new EXOSAT observations of the DQ Her type cataclysmic variable TV Col are presented. The period of the 1–10 kev X-ray pulsation associated with the white-dwarf rotation is now established as 1911 s. The pulsations are most pronounced in the lower energy channels (1–3.5 keV). The X-ray light curve shows absorption features associated with the orbital period of the system.

scholarly journals Dwarf Nova-Like Outburst of Short-Period Intermediate Polar HT Camelopardalis

2004 ◽  
Vol 194 ◽  
pp. 259-259
Author(s):  
R. Ishioka ◽  
Keyword(s):  
Orbital Period ◽  
Alternative Interpretation ◽  
Cataclysmic Variable ◽  
Optical Counterpart ◽  
X Ray ◽  
Dwarf Nova ◽  
Spin Period ◽  
Photometric Observations ◽  
Sky Survey ◽  
Short Period

Our time-series photometric observations of a short outburst of HT Cam in 2001 strongly suggest that disk instabilities occurred during the outburst.HT Cam is a cataclysmic variable identified as the optical counterpart of the hard X-ray source RX J0757.0+6306, discovered during the ROSAT All-Sky Survey. Tovmassian et al. (1998) suggested that this object is an intermediate polar with a shortest orbital period of 80.92min and a spin period of 8.52min. However, the existence of dwarf nova-like outbursts and the short orbital period allowed an alternative interpretation that it may be an SU UMa-type dwarf nova or WZ Sge-type stars (Tovmassian et al. 1998).

scholarly journals Discovery of a new WZ Sagittae-type cataclysmic variable in the Kepler/K2 data

2019 ◽  
Vol 490 (4) ◽  
pp. 5551-5559 ◽  
Author(s):  
R Ridden-Harper ◽  
B E Tucker ◽  
P Garnavich ◽  
A Rest ◽  
S Margheim ◽  
...  
Keyword(s):  
Light Curve ◽  
Power Law ◽  
Orbital Period ◽  
Type System ◽  
Cataclysmic Variable ◽  
Linear Rise ◽  
Early Rise ◽  
Power Law Index ◽  
Nova Outburst ◽  
Unusual Type

ABSTRACT We identify a new, bright transient in the K2/Kepler Campaign 11 field. Its light curve rises over 7 mag in a day and then declines 3 mag over a month before quickly fading another 2 mag. The transient was still detectable at the end of the campaign. The light curve is consistent with a WZ Sge-type dwarf nova outburst. Early superhumps with a period of 82 min are seen in the first 10 days and suggest that this is the orbital period of the binary, which is typical for the WZ Sge class. Strong superhump oscillations develop 10 days after peak brightness with periods ranging between 83 and 84 min. At 25 days after the peak brightness a bump in the light curve appears to signal a subtle rebrightening phase implying that this was an unusual type-A outburst. This is the only WZ Sge-type system observed by K2/Kepler during an outburst. The early rise of this outburst is well fitted with a broken power law. In first 10 h, the system brightened linearly and then transitioned to a steep rise with a power-law index of 4.8. Looking at archival K2/Kepler data and new TESS observations, a linear rise in the first several hours at the initiation of a superoutburst appears to be common in SU Ursa Majoris stars.

scholarly journals ASASSN-14ho: Longest-period dwarf nova with multiple rebrightenings

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Taichi Kato
Keyword(s):  
Mass Transfer ◽  
Radial Velocity ◽  
Accretion Disks ◽  
Orbital Period ◽  
Formal Solution ◽  
Dwarf Novae ◽  
X Ray ◽  
Dwarf Nova ◽  
Orbital Periods ◽  
The Stability

Abstract The post-outburst rebrightening phenomenon in dwarf novae and X-ray novae is still one of the most challenging subjects for theories of accretion disks. It has been widely recognized that post-outburst rebrightenings are a key feature of WZ Sge-type dwarf novae, which predominantly have short (≲0.06 d) orbital periods. The author found four post-outburst rebrightenings in ASASSN-14ho during its 2014 outburst, whose orbital period was recently measured to be exceptionally long [0.24315(10) d]. Using the formal solution of the radial velocity study in the literature, this paper discusses the possibility that this object could be an SU UMa-type dwarf nova near the stability border of the 3 : 1 resonance, despite its exceptionally long orbital period. Such objects are considered to be produced if mass transfer occurs after the secondary has undergone significant nuclear evolution, and they may be hidden in a significant number of dwarf novae showing multiple post-outburst rebrightenings.

scholarly journals EXTENSIVE PHOTOMETRY OF V1838 AQL DURING THE 2013 SUPEROUTBURST

2019 ◽  
Vol 55 (1) ◽  
Author(s):  
J. Echevarría ◽  
E. de Miguel ◽  
J. V. Hernández Santisteban ◽  
R. Michel ◽  
R. Costero ◽  
...  
Keyword(s):  
Orbital Period ◽  
Careful Examination ◽  
Cataclysmic Variable ◽  
Mass Star ◽  
Quiescent State ◽  
Photometric Study ◽  
Mass Ratio ◽  
Low Mass

We present an in-depth photometric study of the 2013 superoutburst of the recently discovered cataclysmic variable V1838 Aql and subsequent photometry near its quiescent state. A careful examination of the development of the superhumps is presented. Our best determination of the orbital period is Porb = 0.05698(9) days, based on the periodicity of early superhumps. Comparing the superhump periods at stages A and B with the early superhump value we derive a period excess of ǫ = 0.024(2) and a mass ratio of q = 0.10(1). We suggest that V1838 Aql is approaching the orbital period minimum and thus has a low-mass star as a donor instead of a substellar object.

scholarly journals CRTS J035010.7 + 323230, a new eclipsing polar in the cataclysmic variable period gap

2019 ◽  
Vol 488 (2) ◽  
pp. 2881-2891 ◽  
Author(s):  
Paul A Mason ◽  
Natalie K Wells ◽  
Mokhine Motsoaledi ◽  
Paula Szkody ◽  
Emmanuel Gonzalez
Keyword(s):  
Light Curve ◽  
White Dwarf ◽  
Spectral Energy Distribution ◽  
Semimajor Axis ◽  
Spectral Energy ◽  
Cataclysmic Variable ◽  
Show Evidence ◽  
Optical Light Curve ◽  
Photometric Monitoring ◽  
Orbital Cycle

ABSTRACT We report the discovery of a new eclipsing polar, CRTS J035010.7+323230 (hereafter CRTS J0350+3232). We identified this cataclysmic variable (CV) candidate as a possible polar from its multiyear Catalina Real-Time Transient Survey (CRTS) optical light curve. Photometric monitoring of 22 eclipses in 2015 and 2017 was performed with the 2.1-m Otto Struve Telescope at McDonald Observatory. We derive an unambiguous high-precision ephemeris. Strong evidence that CRTS J0350 + 3232 is a polar comes from optical spectroscopy obtained over a complete orbital cycle using the Apache Point Observatory 3.5-m telescope. High velocity Balmer and He ii λ4686Å emission-line equivalent width ratios, structures, and variations are typical of polars and are modulated at the same period, 2.37 h (142.3 min), as the eclipse to within uncertainties. The spectral energy distribution and luminosity is found to be comparable to that of AM Herculis. Pre-eclipse dips in the light curve show evidence for stream accretion. We derive the following tentative binary and stellar parameters assuming a helium composition white dwarf and a companion mass of 0.2 M⊙: inclination i  = 74.68° ± 0.03°, semimajor axis a  = 0.942 ± 0.024 R⊙, and masses and radii of the white dwarf and companion, respectively: M1  = 0.948 $^{+0.006}_{-0.012}$ M⊙, R1  = 0.00830 $^{+0.00012}_{-0.00006}$ R⊙, and R2  = 0.249 ± 0.002 R⊙. As a relatively bright (V ∼ 17–19 mag), eclipsing, period-gap polar, CRTS J0350 + 3232 will remain an important laboratory for the study of accretion and angular momentum evolution in polars.

scholarly journals The intermediate polar cataclysmic variable GK Persei 120 years after the nova explosion: a first dynamical mass study

2021 ◽  
Author(s):  
A Álvarez-Hernández ◽  
M A P Torres ◽  
P Rodrí guez-Gil ◽  
T Shahbaz ◽  
G C Anupama ◽  
...  
Keyword(s):  
Light Curve ◽  
White Dwarf ◽  
Rotational Velocity ◽  
Cataclysmic Variable ◽  
Radial Velocity Curve ◽  
Dynamical Study ◽  
Dynamical Mass ◽  
Orbital Inclination ◽  
X Ray ◽  
Dwarf Nova

Abstract We present a dynamical study of the intermediate polar and dwarf nova cataclysmic variable GK Per (Nova Persei 1901) based on a multi-site optical spectroscopy and R-band photometry campaign. The radial velocity curve of the evolved donor star has a semi-amplitude K2 = 126.4 ± 0.9 km s−1 and an orbital period P = 1.996872 ± 0.000009 d. We refine the projected rotational velocity of the donor star to vrotsin i = 52 ± 2 km s−1 which, together with K2, provides a donor star to white dwarf mass ratio q = M2/M1 = 0.38 ± 0.03. We also determine the orbital inclination of the system by modelling the phase-folded ellipsoidal light curve and obtain i = 67○ ± 5○. The resulting dynamical masses are $M_{1}=1.03^{+0.16}_{-0.11} \, \mathrm{M}_{\odot }$ and $M_2 = 0.39^{+0.07}_{-0.06} \, \mathrm{M}_{\odot }$ at 68 per cent confidence level. The white dwarf dynamical mass is compared with estimates obtained by modelling the decline light curve of the 1901 nova event and X-ray spectroscopy. The best matching mass estimates come from the nova light curve models and an X-ray data analysis that uses the ratio between the Alfvén radius in quiescence and during dwarf nova outburst.

scholarly journals Results of 5-year photometric monitoring of the intermediate polar V2306 Cygni: correction of the orbital period and evidence of 2-day periodicity

2015 ◽  
Vol 5 (1) ◽  
pp. 17-20
Author(s):  
V. Breus ◽  
K. Petrík ◽  
S. Zoła ◽  
A. Baransky ◽  
T. Hegedus
Keyword(s):  
Light Curve ◽  
Accretion Disk ◽  
Orbital Period ◽  
White Dwarf ◽  
Cataclysmic Variable ◽  
Firm Conclusion ◽  
Spin Period ◽  
Photometric Monitoring

We present the results of 6 years of photometric monitoring of the magnetic cataclysmic variable V2306 Cygni (formerly known as 1WGAJ1958.2+3232) obtained at collaborating observatories. Using (O-C) analysis we tried to study variability of the spin period of the white dwarf, however we cannot make a firm conclusion based on the scatter. Simultaneously, using (O-C) diagram of orbital minima, we found that the value of 0.181545(3) days better corresponds with the light curve, than do previously published orbital period values. We also found that the variability has a 2.01 day period; this variability may be interpreted as possible precession of the accretion disk in this system.

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