Bibcode
                                    
                            Sivakoff, G. R.; Miller-Jones, J.; Fox, O.; Linares, M.; Altamirano, D.; Russell, D.
    Bibliographical reference
                                    The Astronomer's Telegram, #2302
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                        11
            
                        2009
            
  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.