7–11 Sept 2026
Cefalù
Europe/Rome timezone

SAX J1808.8-3658's 2025 outburst in the multi-wavelength regime

Not scheduled
20m
Cefalù

Cefalù

Cefalù, province of Palermo, Sicily. Sala delle Capriate in the Town Hall (Piazza Duomo).
Poster

Speaker

Dr Kelebogile Gasealahwe (UCT, SARAO)

Description

Discovered in 1998, SAX J1808.8-3658 remains the archetypal Accreting millisecond X-ray pulsar (AMXP) (Wijnands & van der Klis 1998). After numerous outbursts since its discovery, recurring every 2 - 4 years, the source entered into a new outburst mid 2025. A day after the outburst was announced by the X-ray Binary New Early Warning System (XB-NEWS), we began observations with the MeerKAT radio telescope. In the L-band configuration (1.28 GHz), MeerKAT closely monitored the outburst from 7 August 2025 to 27 September 2025. We present a multi-wavelength representation of the lightcurves; radio (MeerKAT), X-ray (Neil Gehrels Swift XRT) and optical (Las Cumbres Observatory). The lightcurves illustrate that the source encountered several rebrightening events in all the wavebands. We identified several hard spectral states among the X-ray spectra and as a result placed the source on the radio | X-ray plane. The preliminary results place the source closely among the positions of previously recorded outbursts.

Author

Dr Kelebogile Gasealahwe (UCT, SARAO)

Presentation materials