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 Maximum Magnitude Vs. Rate of Decline for Novae of the LMC

1990 ◽  
Vol 122 ◽  
pp. 71-72
Author(s):  
M. Capaccioli ◽  
M. Della Valle ◽  
M. D’Onofrio ◽  
L. Rosino
Keyword(s):  
Close Agreement ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Distance Modulus ◽  
Maximum Magnitude ◽  
Rr Lyrae ◽  
Rate Of Decline

AbstractWe derive the distance modulus of the Large Magellanic Cloud (LMC) by applying the new calibrated relationship between maximum magnitude and rate of decline (MMRD). The result, , is in close agreement with the most recent determinations based on RR Lyrae and Cepheids. We also discuss the properties of the MMRD of M31 and of the LMC.

scholarly journals Peculiar Abundances in CV Secondary Stars: Revising their Evolutionary History?

2004 ◽  
Vol 194 ◽  
pp. 249-249
Author(s):  
Thomas E. Harrison ◽  
Steve B. Howell ◽  
Joni J. Johnson ◽  
Heather L. Osborne ◽  
Derek Homeier
Keyword(s):  
Orbital Period ◽  
Evolutionary History ◽  
Cataclysmic Variables ◽  
Secondary Star ◽  
Sodium Calcium ◽  
Short Period ◽  
Show Evidence ◽  
K Band

We have recently completed an infrared (K-band) spectroscopic survey of two dozen cataclysmic variables. The systems range in orbital period from Рorb = 1-35 hr (EF Eri), to Рorb = 11.0 hr (V442 Cen). We detect the secondary star in every system.Nearly all of the CVs in which we can clearly see the secondary have weak CO features. Most show evidence for enhanced levels of 13CO. In addition, we see apparent enhancements and/or deficits of such species as sodium, calcium, titanium, magnesium, silicon, and iron. In addition, we find a few lines that we have been unable to identify (such as the strong feature we call “cataclysmicum” at 2.2767 μm seen in the spectrum of EF Eri, and two other very short period CVs).

scholarly journals Spectroscopy of the Primary and Secondary Components of the Dwarf Nova AH Herculis

1987 ◽  
Vol 93 ◽  
pp. 123-124
Author(s):  
A. Bruch
Keyword(s):  
Cataclysmic Variables ◽  
Dwarf Nova ◽  
Secondary Star ◽  
V Band ◽  
Visual Magnitude ◽  
Total Light ◽  
Composite Nature ◽  
Astronomy And Astrophysics ◽  
Calar Alto ◽  
Complete Account

AbstractThe dwarf nova AH Her belongs to those cataclysmic variables which show a composite spectrum in the optical range, containing emission lines from the accretion disk and absorptions from the secondary star. This has been shown by Horne et al. (1986). Anticipating the composite nature of the spectrum from the the B-V colour of AH Her, which is intrinsically redder then , I took spectra of the system in four nights in June 1984 at the 1.2-m-telescope of the DSAZ on Calar Alto in order to detect the secondary component. The wavelength range observed was 5300 Å – 7150 Å. Apart from H in emission which behaves in the same way as described by Horne et al., the spectra show in fact a definite absorption of the Na D lines to be attributed to the secondary star. The linestrength and the absence of any strong TiO features confines the spectral type of the secondary to between K2 and MO. It is possible to calculate the relative contributions of the primary and secondary to the total light at the wavelength of Na D as a function of the exact spectral subtype of the secondary, using the measured equivalent width of the Na D lines. Taking the spectral gradient of primary and secondary from the current literature the same can be done for the effective wavelength of the V band. It is then straightforward to calculate the system’s absolute visual magnitude and the distance. It turns out that AH Her is one of the intrinsically brightest dwarf novae known, regardless of the exact spectral subtype of the secondary.A complete account of the observations of AH Her and of the interpretations is given in a paper which has been submitted to Astronomy and Astrophysics.

scholarly journals V1493 AQL an Extremely Distant Nova?

2004 ◽  
Vol 194 ◽  
pp. 236-236
Author(s):  
A. Dobrotka ◽  
A. Retter ◽  
L. Hric ◽  
R. Novak ◽  
O. Shemmer ◽  
...  
Keyword(s):  
Light Curve ◽  
Orbital Period ◽  
Cataclysmic Variables ◽  
Photometric Data ◽  
Expansion Velocity ◽  
Ccd Photometry ◽  
Time Estimates

Analysis of CCD photometry performed during 12 nights and the estimate of the distance based on the light curve is presented. The photometric data is modulated with a period of 3.7 h, which we interpret as the orbital period above the period gap distribution of cataclysmic variables. The VSNET light curve combined with data from IAU Circulars suggests a distance of 4.5±0.4 kpc based on t2/t3 time estimates. Two spectra 11 days after the maximum were taken. The expansion velocity of the envelope was derived to be 1658±62 km s–1.

scholarly journals Long-Term Variability and Outburst Activity of FS Aurigae: Further Evidence for a Third Body in the System

2011 ◽  
Vol 7 (S282) ◽  
pp. 79-80
Author(s):  
V. Neustroev ◽  
G. Sjoberg ◽  
G. Tovmassian ◽  
S. Zharikov ◽  
T. Arranz Heras ◽  
...  
Keyword(s):  
Transfer Rate ◽  
Mass Transfer Rate ◽  
Cataclysmic Variables ◽  
Close Binary ◽  
Third Body ◽  
Secondary Star ◽  
Long Term Monitoring ◽  
Binary Orbit ◽  
Term Monitoring

AbstractFS Aurigae is famous for a variety of uncommon and puzzling periodic photometric and spectroscopic variabilities which do not fit well into any of the established sub-classes of cataclysmic variables. Here we present preliminary results of long-term monitoring of the system, conducted during the 2010-2011 observational season. We show that the long-term variability of FS Aur and the character of its outburst activity may be caused by variations in the mass transfer rate from the secondary star as the result of eccentricity modulation of a close binary orbit induced by the presence of a third body on a circumbinary orbit.

scholarly journals Ultraviolet Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 205-205 ◽  
Author(s):  
F. Verbunt
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Type Systems ◽  
Terminal Velocity ◽  
Dwarf Novae ◽  
Preliminary Results ◽  
System Type ◽  
International Ultraviolet Explorer ◽  
Flux Level ◽  
Ultraviolet Observations

AbstractThe preliminary results of the analysis of more than 1000 spectra of cataclysmic variables in the archive of the International Ultraviolet Explorer were presented at the meeting. To characterize the slope of the spectra I use F = log(f1460Å/f2880Å). For most spectra F lies between 0.2 and 0.7. No correlation of F with orbital period, inclination, system type or (for dwarf novae) length of the interoutburst interval are found, apart from somewhat lower values of F for DQ Her type systems. Out of 16 dwarf novae for which spectra both at outburst maximum and minimum are available 11 show no large difference in F between maximum and minimum, and in 5 F declines with the flux level. Out of 6 dwarf novae 5 show very red spectra during the rise to maximum, and 1 shows slopes during rise similar to those during decline.In the ultraviolet resonance lines, due to a wind from the disc, no correlation is found between inclination and terminal velocity.

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 CVs Around the Minimum Orbital Period

2015 ◽  
Vol 2 (1) ◽  
pp. 41-45
Author(s):  
S. Zharikov ◽  
G. Tovmassian
Keyword(s):  
Accretion Disk ◽  
Accretion Disks ◽  
Orbital Period ◽  
Cataclysmic Variables ◽  
Outer Edge ◽  
Light Curves ◽  
Mass Ratio ◽  
Period Limit ◽  
Bounce Back ◽  
The Continuum

We discussed features of Cataclysmic Variables at the period minimum. In general, most of them must be WZ Sge-type objects. Main characteristics of the prototype star (WZ Sge) are discussed. A part of WZ Sge-type objects has evolved past the period limit and formed the bounce back systems. We also explore conditions and structure of accretion disks in such systems. We show that the accretion disk in a system with extreme mass ratio grows in size reaching a 2:1 resonance radius and are relatively cool. They also become largely optically thin in the continuum, contributing to the total flux less than the stellar components of the system. In contrast, the viscosity and the temperature in spiral arms formed at the outer edge of the disk are higher and their contribution in continuum plays an increasingly important role. We model such disks and generate light curves which successfully simulate the observed double-humped light curves in the quiescence.

Angular Momentum Losses and the Orbital Period Distribution of Cataclysmic Variables below the Period Gap: Effects of Circumbinary Disks

2005 ◽  
Vol 635 (2) ◽  
pp. 1263-1280 ◽  
Author(s):  
Bart Willems ◽  
Ulrich Kolb ◽  
Eric L. Sandquist ◽  
Ronald E. Taam ◽  
Guillaume Dubus
Keyword(s):  
Angular Momentum ◽  
Orbital Period ◽  
Cataclysmic Variables ◽  
Period Distribution ◽  
Gap Effects
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