The residual orbital eccentricity in close binaries

Lanza, A. F.; Rodonò, M.

doi:10.1051/0004-6361:20010938

Cited by 21 publications

(20 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These processes could very well be density fluctuations in a convective envelope of the donor star (see ). Hence, the eccentricity of PSR J2051−0827 (6.2 × 10 −5 ) is much larger than the expected residual eccentricities (≤10 −8 ) for binary millisecond pulsars with a similar orbital period (Lanza & Rodonò 2001).…”

Section: Timing Resultsmentioning

confidence: 75%

Evidence for gravitational quadrupole moment variations in the companion of PSR J2051−0827

Lazaridis¹,

Verbiest²,

Tauris³

et al. 2011

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We have conducted radio timing observations of the eclipsing millisecond binary pulsar PSR J2051−0827 with the European Pulsar Timing Array network of telescopes and the Parkes radio telescope, spanning over 13 yr. The increased data span allows significant measurements of the orbital eccentricity, e = (6.2 ± 1.3) × 10 −5 , and composite proper motion, μ t = 7.3 ± 0.4 mas yr −1 . Our timing observations have revealed secular variations of the projected semimajor axis of the pulsar orbit which are much more extreme than those previously published and of the orbital period of the system. Investigations of the physical mechanisms producing such variations confirm that the variations of the semimajor axis are most probably caused by classical spin-orbit coupling in the binary system, while the variations in orbital period are most likely caused by tidal dissipation leading to changes in the gravitational quadrupole moment of the companion.

show abstract

Section: Timing Resultsmentioning

confidence: 75%

Evidence for gravitational quadrupole moment variations in the companion of PSR J2051−0827

Lazaridis¹,

Verbiest²,

Tauris³

et al. 2011

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Eggleton (2006) discusses these processes and their associated amplitudes and timescales extensively. Random convective motions in the M dwarf could also lead to an eccentric orbit, since they induce fluctuations in the exterior gravitational field (Phinney 1992;Lanza & Rodonò 2001).…”

Section: Discussionmentioning

confidence: 99%

THE RØMER DELAY AND MASS RATIO OF THE sdB+dM BINARY 2M 1938+4603 FROMKEPLERECLIPSE TIMINGS

Barlow

Wade

Liss

2012

ApJ

View full text Add to dashboard Cite

The eclipsing binary system 2M 1938+4603 consists of a pulsating hot subdwarf B star and a cool M dwarf companion in an effectively circular three-hour orbit. The light curve shows both primary and secondary eclipses, along with a strong reflection effect from the cool companion. Here we present constraints on the component masses and eccentricity derived from the Rømer delay of the secondary eclipse. Using six months of publicly-available Kepler photometry obtained in Short Cadence mode, we fit model profiles to the primary and secondary eclipses to measure their centroid values. We find that the secondary eclipse arrives on average 2.06 ± 0.12 s after the midpoint between primary eclipses. Under the assumption of a circular orbit, we calculate from this time delay a mass ratio of q = 0.2691 ± 0.0018 and individual masses of M sd = 0.372 ± 0.024 M ⊙ and M c = 0.1002 ± 0.0065 M ⊙ for the sdB and M dwarf, respectively. These results differ slightly from those of a previously-published light curve modeling solution; this difference, however, may be reconciled with a very small eccentricity, e cos ω ≈ 0.00004. We also report an orbital period decrease ofṖ = (-1.23 ± 0.07) × 10 −10 .

show abstract

“…The quadrupole moment variation does not excite any orbital eccentricity because the period of the oscillation of the angle α is much longer than the orbital period (cf. Phinney 1992;Lanza & Rodonò 2001), so we shall assume r = 0 in our equations of motion. The first of equations ( 24) with r = 0 provides a generalization of the Kepler III law that we write…”

Section: Equations Of Motion Of the Binary Systemmentioning

confidence: 99%

Internal magnetic fields, spin-orbit coupling, and orbital period modulation in close binary systems

Lanza

2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We introduce a new model to explain the modulation of the orbital period observed in close stellar binary systems based on an angular momentum exchange between the spin of the active component and the orbital motion. This spin-orbit coupling is not due to tides, but is produced by a non-axisymmetric component of the gravitational quadrupole moment of the active star due to a persistent non-axisymmetric internal magnetic field. The proposed mechanism easily satisfies all the energy constraints having an energy budget ∼ 10 2 − 10 3 times smaller than those of previously proposed models and is supported by the observations of persistent active longitudes in the active components of close binary systems. We present preliminary applications to three well-studied binary systems to illustrate the model. The case of stars with hot Jupiters is also discussed showing that no significant orbital period modulation is generally expected on the basis of the proposed model.

show abstract

The residual orbital eccentricity in close binaries

Cited by 21 publications

References 25 publications

Evidence for gravitational quadrupole moment variations in the companion of PSR J2051−0827

Evidence for gravitational quadrupole moment variations in the companion of PSR J2051−0827

THE RØMER DELAY AND MASS RATIO OF THE sdB+dM BINARY 2M 1938+4603 FROMKEPLERECLIPSE TIMINGS

Internal magnetic fields, spin-orbit coupling, and orbital period modulation in close binary systems

Contact Info

Product

Resources

About