Aql X-1 transition towards the soft (banana) state accompanied by radio/NIR detection

Sivakoff, G. R.; Miller-Jones, J.; Fox, O.; Linares, M.; Altamirano, D.; Russell, D.
Bibliographical reference

The Astronomer's Telegram, #2302

Advertised on:
11
2009
Number of authors
6
IAC number of authors
0
Citations
3
Refereed citations
1
Description
The currently active neutron star transient and atoll source Aql X-1 (Linares et al., ATEL #2288) has begun the transition from the hard (extreme island) state to the soft (banana) state (Rodriguez et al. ATEL #2299). This transition likely began around 2009 Nov 15 (MJD = 55150). The latest RXTE PCA observation (2009 Nov 17, MJD=55152.17+/-0.02, 2-60 keV fractional rms variability amplitude of ~11% for 0.1-10 Hz) indicates that the source is in the intermediate (island) state.