The Fast Spiral-in of the companion star to the black hole XTE J1118+480.

Fig. 1: Top panel: orbital phase shift at the time of the inferior conjunction (orbital phase 0), Tn , of the secondary star in the low-mass black hole X-ray binary XTE J1118+480 versus the orbital cycle number, n, folded on the best-fit parabolic fit. Gr
Fig. 1: Top panel: orbital phase shift at the time of the inferior conjunction (orbital phase 0), Tn , of the secondary star in the low-mass black hole X-ray binary XTE J1118+480 versus the orbital cycle number, n, folded on the best-fit parabolic fit. Gr
Advertised on
References
2012 ApJ, 744, L25

We report the detection of an orbital period decay of (dP/dt)= -1.83+-0.66 ms yr–1  in the black hole X-ray binary XTE J1118+480. This corresponds to a period change of –0.85 ± 0.30 μs per orbital cycle, which is ~150 times larger than expected from the emission of gravitational waves. These observations cannot be reproduced by conventional models of magnetic braking even when including significant mass loss from the system. The spiral-in of the star is either driven by magnetic braking under extremely high magnetic fields in the secondary star or by a currently unknown process, which will have an impact on the evolution and lifetime of black hole X-ray binaries.

News type
Research news

It may interest you

  • alpha_plot_density_gamma_b
    Research news
    The universal variability of the stellar initial mass function probed by the TIMER survey
    The universality of the stellar initial mass function (IMF) is one of the most widespread assumptions in modern Astronomy and yet, it might be flawed. While observations in the Milky Way generally support an IMF that is invariant with respect to the local conditions under which stars form, measurements of massive early-type galaxies systematically point towards a non-universal IMF. To bridge the gap between both sets of evidence, in this work we measured for the first time the low-mass end of the IMF from the integrated spectra of a Milky Way-like galaxy, NGC3351. We found that the slope of
    Advertised on
  • Asteroid reflectance spectra from Gaia DR3
    Research news
    Asteroid reflectance spectra from Gaia DR3: Near-UV in primitive asteroids
    Asteroids are the remnants of the planetary formation in the Solar System and so, their study helps us to understand the conditions during the early stages of the formation of our planetary system. Among asteroids, those classified as primitives present similar spectra to that of carbonaceous chondrites, i.e., they are rich in carbon and organic compounds and silicates altered by the presence of liquid water (phyllosilicates). Primitive asteroids are well characterized in various wavelength regions, showing their most diagnostic feature at 3μm. However, there is a lack of information in the
    Advertised on
  • Action space (normalized to the sum of the three actions of motion, Jtot) of Gaia RVS stars
    Research news
    The Metal-Poor Edge of the Milky Way’s Thin Disk
    The formation and evolution of the disk of our Galaxy, the Milky Way, remains an enigma in astronomy. In particular, the relationship between the thick disk and the thin disk —two key components of the Milky Way— is still unclear. Understanding the chemical and dynamical properties of the stars within these disks is crucial, especially in the parameter spaces where their characteristics overlap, such the metallicity regime around [Fe/H] ~ -0.7, which marks the metal-poor end of the thin disk, higher than that of the thick disk. This is often interpreted as an indication that the thin disk
    Advertised on