On February 25, a hard X-ray source was clearly detected by astronomers monitoring the nova, V1369 Cen, with the Swift satellite.
A subsequent observation on March 8 revealed that the X-ray source had brightened. Further observations are planned and will confirm or deny this as the start of the super-soft source phase.
See ATel 5966 for more details.
V339 Del has recently emerged from the Swift Sun constraint. The final observation before the start of the constraint, on 2014 January 6 (day 144.5 after optical detection), yielded an X-ray count rate of ~40 count s-1. However, by March 4 (day 202), the count rate had dropped to ~0.8 count s-1. A further series of observations on March 9 (day 206-207) revealed a continued count rate decline to ~0.4 count s-1.
Despite the drop in count rate, the current X-ray spectrum of V339 Del is still soft, with almost all counts below 1 keV.
See ATel 5967 for full details.
Exciting times for professional and amateur nova investigators!