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.
|Original language||English (US)|
|Journal||The Astronomer's Telegram|
|State||Published - Nov 1 2009|
- Request for Observations
- Neutron Stars