scholarly journals 1RXS J232953.9+062814: A Dwarf Nova with a 64 Minute Orbital Period and a Conspicuous Secondary Star

2002 ◽  
Vol 567 (1) ◽  
pp. L49-L52 ◽  
Author(s):  
John R. Thorstensen ◽  
William H. Fenton ◽  
Joseph O. Patterson ◽  
Jonathan Kemp ◽  
Thomas Krajci ◽  
...  
Keyword(s):  
Orbital Period ◽  
Dwarf Nova ◽  
Secondary Star

scholarly journals QZ Serpentis: A Dwarf Nova with a 2 Hour Orbital Period and an Anomalously Hot, Bright Secondary Star

2002 ◽  
Vol 114 (800) ◽  
pp. 1117-1123 ◽  
Author(s):  
John R. Thorstensen ◽  
William H. Fenton ◽  
Joseph Patterson ◽  
Jonathan Kemp ◽  
Jules Halpern ◽  
...  
Keyword(s):  
Orbital Period ◽  
Dwarf Nova ◽  
Secondary Star

scholarly journals Superoutbursts and Superhumps of SU UMa Stars

1988 ◽  
Vol 108 ◽  
pp. 238-239
Author(s):  
Yoji Osaki ◽  
Masahito Hirose
Keyword(s):  
Accretion Disk ◽  
Orbital Period ◽  
White Dwarf ◽  
Binary Systems ◽  
Roche Lobe ◽  
Light Curves ◽  
Close Binary ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Close Binary Systems

SU UMa stars are one of subclasses of dwarf novae. Dwarf novae are semi-detached close binary systems in which a Roche-lobe filling red dwarf secondary loses matter and the white dwarf primary accretes it through the accretion disk. The main characteristics of SU UMa subclass is that they show two kinds of outbursts: normal outbursts and superoutbursts. In addition to the more frequent narrow outbursts of normal dwarf nova, SU UMa stars exhibit “superoutbursts”, in which stars reach about 1 magnitude brighter and stay longer than in normal outburst. Careful photometric studies during superoutburst have almost always revealed the “superhumps”: periodic humps in light curves with a period very close to the orbital period of the system. However, the most curious of all is that this superhump period is not exactly equal to the orbital period, but it is always longer by a few percent than the orbital period.

The Orbital Period and Variability of the Dwarf Nova WW Ceti

1996 ◽  
Vol 111 ◽  
pp. 2077 ◽  
Author(s):  
F. A. Ringwald ◽  
John R. Thorstensen ◽  
R. Kent Honeycutt ◽  
Robert Connon Smith
Keyword(s):  
Orbital Period ◽  
Dwarf Nova

scholarly journals On the Evolution of the Nova-like Variable AE Aquarii

2004 ◽  
Vol 190 ◽  
pp. 300-306
Author(s):  
P. J. Meintjes
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
White Dwarf ◽  
Time Scale ◽  
Critical Mass ◽  
Current Phase ◽  
Thermal Activity ◽  
Secondary Star ◽  
Wind Theory ◽  
Mass Ejection

AbstractIt is shown here that the peculiar properties of AE Aqr can can be accounted for if the mass transfer from an evolved 0.7M⊙ secondary K4-5 star (qi ≈ 0.8, i.e. < 1) initiated when the orbital period of the binary was Porb,i ≈ 8.5 hours and the white dwarf period P*,i ≈ 1 hour. This resulted in a significant amount of orbital angular momentum being accreted by the white dwarf in an initial discless spin-up phase towards P* ≈ 0.1 Porb,i. This destabilized the mass transfer, resulting in a run-away mass transfer from the secondary that lasted for approximately 104 years, with the orbital period evolving to Porb ≈ 11 hours until a critical mass ratio of qcrit = 0.73 had been reached. In this phase the mass transfer from the secondary occurred at a rapid rate of approximately Ṁ2 ≈ 1020 g s-1, resulting in an accretion disc which spun-up the white dwarf to a period of approximately P* ≈ 33 s. For all q ≤ qcrit = 0.73 the mass transfer proceeded on the thermal time scale of the secondary star, i.e. at a much slower rate, resulting in the binary converging and forcing AE Aqr into the propeller phase. Applying stellar wind theory, this allow an estimate of the polar magnetic field of the secondary star, which is of the order of B° ≈ (1600 – 2000) G. It has been shown here that the duration of mass transfer phase q = qcrit → 0.67 (now) lasted for approximately tṀ2 ~ 107 years, similar to the spin-down time scale of the white dwarf, tsd = P*/P* ≈ 107 years. The propeller ejection of matter in the current phase results in the dissipation of mhd power of Lmhd ≈ 1034 erg s-1, probably channeled into mass ejection and non-thermal activity. This explains the non-thermal outbursts that are observed in radio wavelengths, and occasionally also in TeV energies, from AE Aqr.

scholarly journals A Beat Phenomenon in Dwarf Nova Eruptions

1977 ◽  
Vol 42 ◽  
pp. 227-233
Author(s):  
N. Vogt
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
Transfer Rate ◽  
Convection Zone ◽  
Mass Transfer Rate ◽  
Accretion Disc ◽  
Light Curves ◽  
Dwarf Nova ◽  
Beat Phenomenon ◽  
Photoelectric Observations

Photoelectric observations of the dwarf nova VW Hyi, obtained at the end of the December 1975 supermaximum, are presented. After decline from the outburst, the superhump period (0ḍ07622) combines with the orbital period (0ḍ07427) to a beat phenomenon: the O-C’s and the light curves of the orbital hump vary systematically with the phase of the beat period for at least one week after recovery from the supermaximum. It is suggested that the red secondary component, which rotates non-synchroneously with the superhump period, expands slightly at the beginning of a supermaximum and is heated up asymmetrically, probably due to instabilities in its convection zone. In addition, the increased mass transfer rate may trigger the long eruption in the accretion disc while short eruptions originate in the disc without participation of the secondary.

scholarly journals Dwarf Novae in the Shortest Orbital Period Regime. I A New Short Superhump Period Dwarf Nova, OT J055717+683226

2010 ◽  
Vol 62 (1) ◽  
pp. 187-199 ◽  
Author(s):  
Makoto Uemura ◽  
Akira Arai ◽  
Taichi Kato ◽  
Hiroyuki Maehara ◽  
Daisaku Nogami ◽  
...  
Keyword(s):  
Orbital Period ◽  
Dwarf Novae ◽  
Dwarf Nova

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 The Orbital Period of Nova V2540 Ophiuchi (2002)

2005 ◽  
Vol 22 (4) ◽  
pp. 298-305 ◽  
Author(s):  
Tansel Ak ◽  
Alon Retter ◽  
Alex Liu
Keyword(s):  
Orbital Period ◽  
Spiral Structure ◽  
Cataclysmic Variables ◽  
Distance Modulus ◽  
Maximum Magnitude ◽  
Reflection Effect ◽  
Ccd Photometry ◽  
Secondary Star ◽  
Visual Magnitude ◽  
Rate Of Decline

AbstractWe present the results of 26 nights of CCD photometry of the nova V2540 Oph (2002) from 2003 to 2004. We find a period of 0.284781 ± 0.000006 d (6.8347 ± 0.0001 h) in the data. Since this period was present in the light curves taken in both years, with no apparent change in its value or amplitude, we interpret it as the orbital period of the nova binary system. The mass–period relation for cataclysmic variables yields a secondary mass of about 0.75 ± 0.04 M⊙. From maximum magnitude–rate of decline relation, we estimate a maximum absolute visual magnitude of MV = −6.2 ± 0.4 mag. This value leads to an uncorrected distance modulus of (m – M) = 14.7 ± 0.7. By using the interstellar reddening for the location of V2540 Oph, we find a rough estimate for the distance of 5.2 ± 0.8 kpc. We propose that V2540 Oph is either (1) a high-inclination cataclysmic variable showing a reflection effect of the secondary star, or having a spiral structure in the accretion disc, (2) a high-inclination intermediate polar system, or less likely (3) a polar.

scholarly journals Light curve analysis of the eclipsing binary system V781 Tau

2021 ◽  
Vol 2145 (1) ◽  
pp. 012005
Author(s):  
N Lamlert ◽  
W Maithong
Keyword(s):  
Binary System ◽  
Light Curve ◽  
Orbital Period ◽  
Binary Systems ◽  
Curve Analysis ◽  
Photometric System ◽  
Light Curve Analysis ◽  
Eclipsing Binary ◽  
The Public ◽  
Secondary Star

Abstract V781 Tau is one of W UMa eclipsing binary systems whose orbital period is 0.34 days. The 0.7-meter telescope with CCD photometric system in B and V filters was conducted at the Regional Observatory for the Public, Chachoengsao, Thailand during December 2018, UT. The Wilson-Devinney Technique was used for calculating the physical properties of V781 Tau. The results showed the inclination of their orbital is 66.140°±0.14. The effective temperature of the primary and secondary star is 6,060 and 5,881 K, respectively and the degree of contact is 4.38 %

Sign in / Sign up

Export Citation Format

Share Document