Accretion discs around binary stellar systems

Multi-wavelength time-domain astronomy

Stars often form in pairs (binaries), and remain gravitationally bound to one another for many billions of years. Variations in the radiation coming from these systems informs us about the the nature of the stellar companions, their surrounding medium, and the physical processes occuring there.


Accreting Black-hole binary GX339-4

Infrared view of an X-ray binary. From (Buxton et al., 2012).
A binary star system near the end of its life can consist of a compact remnant—black hole, neutron star, or white dwarf—and an evolved stellar companion. The compact object is not directly visible, but its presence is inferred from its gravitational effects and variable brightness due to accretion. These systems often undergo energetic outbursts observable in multiple wavelengths.

Young Stellar Binary KH-15D

Changes in system brightness over multiple observing seasons revealed a hidden companion star. From (Capelo et al., 2012)
Young binary systems form accretion disks, potential sites of planet formation. In the case of KH-15D, the geometry of the system leads to periodic occultations of the central stars by the disk, producing unique light variations and offering clues to the structure and evolution of early stellar systems.

These studies utilized data from ground-based telescopes in Cerro Tololo Inter-American Observatory (Chile), the Gemini Observatory, as well as space-based data from the Spitzer Space Telescope. This work was conducted in collaboration with scientists at Yale University, CT, USA and Wesleyan University, CT, USA.

References

2012

  1. Optical and Near-infrared Monitoring of the Black Hole X-Ray Binary GX 339-4 during 2002-2010
    M. M. Buxton, C. D. Bailyn, H. L. Capelo, and 4 more authors
    The Astrophysical Journal, Jun 2012
  2. Locating the Trailing Edge of the Circumbinary Ring in the KH 15D System
    H. L. Capelo, W. Herbst, S. K. Leggett, and 2 more authors
    The Astrophysical Journal Letters, Sep 2012