scholarly journals The Orbital Period Distribution of Cataclysmic Variables Found by the SDSS

2011 ◽  
Vol 7 (S282) ◽  
pp. 123-124 ◽  
Author(s):  
John Southworth ◽  
Boris T. Gänsicke ◽  
Elmé Breedt
Keyword(s):  
Angular Momentum ◽  
Orbital Period ◽  
Cataclysmic Variables ◽  
Sloan Digital Sky Survey ◽  
Cataclysmic Variable ◽  
Minimum Period ◽  
Period Distribution ◽  
Sky Survey ◽  
Short Period ◽  
Angular Momentum Loss

AbstractThe orbital period is one of the most accessible observables of a cataclysmic variable. It has been a concern for many years that the orbital period distribution of the known systems does not match that predicted by evolutionary theory. The sample of objects discovered by the Sloan Digital Sky Survey has changed this: it shows the long-expected predominance of short-period objects termed the ‘period spike’. The minimum period remains in conflict with theory, suggesting that the angular momentum loss mechanisms are stronger than predicted.

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

scholarly journals Minimum Orbital Period of Cataclysmic Variables

1979 ◽  
Vol 53 ◽  
pp. 504-504
Author(s):  
B. Paczynski ◽  
W. Krzeminski
Keyword(s):  
Mass Transfer ◽  
Angular Momentum ◽  
Orbital Period ◽  
Time Scale ◽  
Transfer Rate ◽  
Main Sequence ◽  
Mass Transfer Rate ◽  
Cataclysmic Variables ◽  
Transfer Rates ◽  
Angular Momentum Loss

The shortest known orbital period of a cataclysmic binary with a hydrogen dwarf secondary filling its Roche lobe is about 80 minutes. Theoretically the shortest possible orbital period for such a system is less than 60 minutes. We tried to explain why the periods shorter than 80 minutes are not observed. We estimated the time scale of angular momentum loss of a cataclysmic binary and the resulting mass transfer rate. The minimum orbital period for a given Ṁ is obtained during the transition of the secondary from the Main Sequence onto the Degenerate Dwarf Sequence. Pmin ∝ Ṁ½ Therefore, only those systems can reach low P for which Ṁ is small. This explains why among the shortest period cataclysmic variables there are no novae: presumably their mass transfer rates are too large. It also indicates that “polars” (AM Her-type stars) and SU UMa-type stars should have low Ṁ.

scholarly journals The Hidden Population of AM CVn Binaries in the Sloan Digital Sky Survey

2015 ◽  
Vol 2 (1) ◽  
pp. 178-182
Author(s):  
P. J. Carter ◽  
T. R. Marsh ◽  
D. Steeghs ◽  
E. Breedt ◽  
C. M. Copperwheat ◽  
...  
Keyword(s):  
Orbital Period ◽  
Cataclysmic Variables ◽  
Sloan Digital Sky Survey ◽  
Space Density ◽  
Hidden Population ◽  
Sky Survey

We present results from a spectroscopic survey designed to uncover AM Canum Venaticorum (AM CVn) binaries hidden in the photometric database of the Sloan Digital Sky Survey (SDSS). The discovery of only 7 new AM CVns in the observed part of our sample suggests a lower space density than previously predicted. Based on the complete g≤19 sample, we calculate an observed space density for AM CVns of (5 ± 3) × 10<sup>−7</sup> pc<sup>−3</sup>. We also compare the cataclysmic variables (CVs) discovered via this survey to those found in the SDSS spectroscopy, and we discuss SBSS 1108+574, an unusually helium-rich CV that has a spectroscopically confirmed orbital period of 55 minutes, well below the CV period minimum (~80 min). SBSS 1108+574 may represent an AM CVn forming via the ‘evolved CV’ formation channel.

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 Life after eruption VIII: The orbital periods of novae

2020 ◽  
Author(s):  
I Fuentes-Morales ◽  
C Tappert ◽  
M Zorotovic ◽  
N Vogt ◽  
E C Puebla ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Binary Star ◽  
Cataclysmic Variables ◽  
Momentum Loss ◽  
Period Distribution ◽  
Angular Momentum Loss ◽  
Orbital Periods ◽  
The Impact ◽  
Crucial Ingredient

Abstract The impact of nova eruptions on the long-term evolution of Cataclysmic Variables (CVs) is one of the least understood and intensively discussed topics in the field. A crucial ingredient to improve with this would be to establish a large sample of post-novae with known properties, starting with the most easily accessible one, the orbital period. Here we report new orbital periods for six faint novae: X Cir (3.71 h), IL Nor (1.62 h), DY Pup (3.35 h), V363 Sgr (3.03 h), V2572 Sgr (3.75 h) and CQ Vel (2.7 h). We furthermore revise the periods for the old novae OY Ara, RS Car, V365 Car, V849 Oph, V728 Sco, WY Sge, XX Tau and RW UMi. Using these new data and critically reviewing the trustworthiness of reported orbital periods of old novae in the literature, we establish an updated period distribution. We employ a binary-star evolution code to calculate a theoretical period distribution using both an empirical and the classical prescription for consequential angular momentum loss. In comparison with the observational data we find that both models especially fail to reproduce the peak in the 3 – 4 h range, suggesting that the angular momentum loss for CVs above the period gap is not totally understood.

scholarly journals Common Envelope Binaries

1976 ◽  
Vol 73 ◽  
pp. 75-80 ◽  
Author(s):  
B. Paczynski
Keyword(s):  
Angular Momentum ◽  
Orbital Period ◽  
Planetary Nebula ◽  
Initial Period ◽  
Cataclysmic Variables ◽  
Lagrangian Point ◽  
Common Envelope ◽  
Evolutionary Scenario ◽  
Short Period ◽  
Contact Binary

When a contact binary expands so much that the stellar surface moves beyond the outer Lagrangian point, a common envelope binary is formed. The suggestion is made that while the two dense stellar nuclei spiral towards each other, the envelope expands and is eventually lost. Most of the angular momentum is lost with the envelope, and therefore the final orbital period may be orders of magnitude shorter than the initial period. V471 Tau could have formed from a binary with a ten year orbital period. Most probably, cataclysmic variables are products of the evolution of systems like V471 Tau. Observational discovery of a short period binary being a nucleus of a planetary nebula would provide very important support for the evolutionary scenario presented in this paper.

scholarly journals Identification of 3XMM J000511.8+634018 as a new polar at Porb = 133.5 min – is it inside or outside the period gap?

2020 ◽  
Vol 637 ◽  
pp. A35
Author(s):  
A. D. Schwope ◽  
H. Worpel ◽  
N. A. Webb ◽  
F. Koliopanos ◽  
S. Guillot
Keyword(s):  
Optical Spectroscopy ◽  
Orbital Period ◽  
Thermal Plasma ◽  
White Dwarf ◽  
Cataclysmic Variables ◽  
Light Curves ◽  
Cataclysmic Variable ◽  
Minimum Period ◽  
X Ray ◽  
Bright Phase

Aims. We aimed to identify the variable X-ray source 3XMM J000511.8+634018, which was serendipitously discovered through routine inspections while the 3XMM catalogue was compiled. Methods. We analysed the archival XMM-Newton observation of the source, obtained BUSCA photometry in three colours, and performed optical spectroscopy with the LBT. These data were supplemented by archival observations from the Zwicky Transient Facility. Results. Based on its optical and X-ray properties, 3XMM J000511.8+634018 is classified as a magnetic cataclysmic variable, or polar. The flux is modulated with a period of 2.22 h (8009.1 ± 0.2 s), which we identify with the orbital period. The bright phases are highly variable in X-ray luminosity from one cycle to the next. The source shows a thermal plasma spectrum typical of polars without evidence of a luminous soft blackbody-like component. It is non-eclipsing and displays one-pole accretion. The X-ray and BUSCA light curves show a stream absorption dip, which suggests an inclination 50° < i <  75°. The phasing of this feature, which occurs at the end of the bright phase, requires a somewhat special accretion geometry with a stream running far around the white dwarf before it is magnetically channelled. The period of this polar falls within the period gap of the cataclysmic variables (2.15−3.18 h), but appears to fall just below the minimum period when only polars are considered.

scholarly journals Periods of Unevolved Late-Type Close Binaries: Evidence of Magnetic Activity

1983 ◽  
Vol 71 ◽  
pp. 391-392
Author(s):  
G. Giuricin ◽  
S. Catalano ◽  
F. Mardirossian ◽  
M. Mezzetti
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Stellar Wind ◽  
Magnetic Activity ◽  
Close Binaries ◽  
Late Type ◽  
Period Distribution ◽  
Short Period ◽  
Angular Momentum Loss ◽  
Magnetic Braking

ABSTRACTOur study of the period distribution of about 200 FGKM-type unevolved close binaries has revealed a strong deficit of short-period systems.This finding may be connected with the occurrence of a very efficient mechanism of orbital angular momentum loss via magnetic braking by stellar wind, in the earliest evolutionary phases.

scholarly journals The Effective Temperature Distribution Function of Cataclysmic Variable White Dwarfs

1987 ◽  
Vol 93 ◽  
pp. 47-51
Author(s):  
E.M. Sion
Keyword(s):  
Distribution Function ◽  
Temperature Distribution ◽  
Orbital Period ◽  
White Dwarf ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Cataclysmic Variable ◽  
Term Evolution ◽  
Effective Temperatures

AbstractWith the recent detection of direct white dwarf photospheric radiation from certain cataclysmic variables in quiescent (low accretion) states, important implications and clues about the nature and long-term evolution of cataclysmic variables can emerge from an analysis of their physical properties. Detection of the underlying white dwarfs has led to a preliminary empirical CV white dwarf temperature distribution function and, in a few cases, the first detailed look at a freshly accreted while dwarf photosphere. The effective temperatures of CV white dwarfs plotted versus orbital period for each type of CV appears to reveal a tendency for the cooler white dwarf primaries to reside in the shorter period systems. Possible implications are briefly discussed.

scholarly journals Pulsating white dwarfs in cataclysmic variables: The marriage of ZZ Cet and dwarf nova

2004 ◽  
Vol 193 ◽  
pp. 382-386 ◽  
Author(s):  
Brian Warner ◽  
Patrick A. Woudt
Keyword(s):  
White Dwarf ◽  
Large Amplitude ◽  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Sloan Digital Sky Survey ◽  
Dwarf Novae ◽  
Dwarf Nova ◽  
Sky Survey

AbstractThere are now four dwarf novae known with white dwarf primaries that show large amplitude non-radial oscillations of the kind seen in ZZ Cet stars. We compare the properties of these stars and point out that by the end of the Sloan Digital Sky Survey more than 30 should be known.

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