The many tones of accretion - to the memory of Tomaso Belloni

Session

Accretion Physics & Spectral States. Session 1.2: States & Transitions

7 Sept 2026, 16:30

Cefalù

74. States and transitions in X-ray binaries

Nathalie Degenaar (University of Amsterdam)

07/09/2026, 16:30

Talk

X-ray binaries exhibit a rich phenomenology of accretion states and transitions, linking changes in the accretion flow to the production of jets, winds, and high-energy emission across a wide range of timescales. In this talk, I will review our current understanding of accretion states and state transitions in neutron star and black hole X-ray binaries, highlighting recent observational...

52. Epic Fail! A Multi-Wavelength Summary of the Surprisingly Short 2024/25 Outburst from EXO 0748-676

Amy Knight (Durham University, UK)

07/09/2026, 17:15

Talk

After sixteen years in quiescence, EXO 0748-676 unexpectedly alerted the world to its return to outburst with a bright X-ray burst in June 2024, having been increasing in brightness since March 2024. However, in stark contrast to its previous outburst (1985 - 2008), EXO 0748-676 returned to quiescence in January 2025, after roughly 10 months in outburst. In this talk, I will present a...

43. The Galactic population of accreting black holes

Jorge Casares (Instituto de Astrofisica de Canarias)

07/09/2026, 17:30

Talk

The Milky Way is thought to be populated with ~103-104 stellar-mass black holes (BHs) that are fed by gas accreted from companion stars in tight orbits. Most of these BHs are transient and exhibit episodic X-ray outbursts on decadal timescales - the smoking gun that led to their discovery. However, since their duty cycles are very low, the vast majority remain hidden in a dormant state,...

18. Optical spectroscopy of the transitional millisecond pulsar PSR J1023+0038

Marco Maria Messa (Istituto Nazionale di Astrofisica (INAF))

07/09/2026, 17:45

Talk

Transitional millisecond pulsars (tMSP) represent a dynamic category of celestial sources that establish a crucial connection between low-mass X-ray binaries and millisecond radio pulsars. These systems exhibit transitions from rotation-powered to accretion-powered states and vice versa, highlighting the tight evolutionary link expected by the so-called recycling scenario. In their active...