A second-order approximation to equatorial null geodesics in the Kerr metric - Application to light deflection in eclipsing compact binaries

Bibcode
1992MNRAS.259..281G
Goicoechea, L. J.; Mediavilla, E.; Buitrago, J.; Atrio, F.
Bibliographical reference

Monthly Notices of the Royal Astronomical Society (ISSN 0035-8711), vol. 259, no. 2, p. 281-292.

Advertised on:
11
1992
Number of authors
4
IAC number of authors
2
Citations
14
Refereed citations
14
Description
We present a second-order analytical expansion of null equatorial geodesics in the Kerr metric. The equations developed are applied to the study of light transit in compact binary systems. We show that the effects arising from path bending have a significant influence on the computed time delays, even at first order of approximation in the Schwarzschild metric, reducing by about 50 percent the lags expected when rectilinear propagation is assumed. We calculate the time delays in the second-order approximation, including the effects derived from light deflection. For systems in which the central object is a rotating black hole, the time lag could even be of the order of minutes. The duration of the eclipse and the amplitude of the lensing effect are also studied and we find a coverage for the lensing effect of almost 180 deg for neutron stars. The influence of the spin of the central object is manifested in the asymmetry of the curve representing time delay versus orbital phase, which is very enhanced in the part affected by lensing.
Type
Refereed
Eclipsing binary stars
Relativity
Neutron stars
Radiative transfer

It may interest you

  • Refereed
    NGTS-28Ab: a short period transiting brown dwarf

    We report the discovery of a brown dwarf orbiting a M1 host star. We first identified the brown dwarf within the Next Generation Transit Survey data, with supporting observations found in TESS sectors 11 and 38. We confirmed the discovery with follow-up photometry from the South African Astronomical Observatory, SPECULOOS-S, and TRAPPIST-S, and

    Henderson, Beth A. et al.

    Advertised on:

    5
    2024
    Bibcode
    2024MNRAS.530..318H
    Citations
    0
  • Refereed
    Teegarden's Star revisited. A nearby planetary system with at least three planets

    The two known planets in the planetary system of Teegarden's Star are among the most Earth-like exoplanets currently known. Revisiting this nearby planetary system with two planets in the habitable zone aims at a more complete census of planets around very low-mass stars. A significant number of new radial velocity measurements from CARMENES

    Dreizler, S. et al.

    Advertised on:

    4
    2024
    Bibcode
    2024A&A...684A.117D
    Citations
    0
  • Refereed
    Light new physics in B →K<SUP>(*)</SUP>ν ν ¯ ?

    The study of the rare decays B →K (*)ν ν ¯ offers a window into the dynamics operating at the electroweak scale, allowing studies of the Standard Model and searches for heavy new physics. However, the analysis of these decays is also potentially sensitive to the on shell production of new light bosons X through the process B →K (*)X . In particular

    Altmannshofer, Wolfgang et al.

    Advertised on:

    4
    2024
    Bibcode
    2024PhRvD.109g5008A
    Citations
    13