The recurrent symbiotic nova V745Â Sco exploded on 2014 February 6 and was observed on February 22 and 23 by the Chandra X-ray Observatory Transmission Grating Spectrometers .
By that time the supersoft source phase had already ended and Chandra spectra are consistent with emission from a hot , shock-heated circumstellar medium with temperatures exceeding 10 ^ { 7 }  K. X-ray line profiles are more sharply peaked than expected for a spherically-symmetric blast wave , with a full width at zero intensity of approximately 2400 km s ^ { -1 } , a full width at half maximum of 1200 \pm 30  km s ^ { -1 } and an average net blueshift of 165 \pm 10  km s ^ { -1 } .
The red wings of lines are increasingly absorbed toward longer wavelengths by material within the remnant .
We conclude that the blast wave was sculpted by an aspherical circumstellar medium in which an equatorial density enhancement plays a role , as in earlier symbiotic nova explosions .
Expansion of the dominant X-ray emitting material is aligned close to the plane of the sky and most consistent with an orbit seen close to face-on .
Comparison of an analytical blast wave model with the X-ray spectra , Swift observations and near-infrared line widths indicates the explosion energy was approximately 10 ^ { 43 } Â erg , and confirms an ejected mass of approximately 10 ^ { -7 } M _ { \odot } .
The total mass lost is an order of magnitude lower than the accreted mass required to have initiated the explosion , indicating the white dwarf is gaining mass and is a supernova Type 1a progenitor candidate .