We present BeppoSAX observations of Nova Velorum 1999 ( V382 Vel ) , done in a broad X-ray band covering 0.1-300 keV only 15 days after the discovery and again after 6 months .
The nova was detected at day 15 with the BeppoSAX instruments which measured a flux F _ { x } \simeq 1.8 \times 10 ^ { -11 } erg cm ^ { -2 } s ^ { -1 } in the 0.1-10 keV range and a 2 \sigma upper limit F _ { x } < 6.7 \times 10 ^ { -12 } erg cm ^ { -2 } s ^ { -1 } in the 15-60 keV range .
We attribute the emission to shocked nebular ejecta at plasma temperature kT \simeq 6 keV .
At 6 months no bright component emerged in the 15-60 keV range , but a bright central supersoft X-ray source appeared .
The hot nebular component previously detected had cooled to a plasma temperature kT < 1 keV .
There was strong intrinsic absorption of the ejecta in the first observation and not in the second , because the column density of neutral hydrogen decreased from N ( H ) \simeq 1.7 \times 10 ^ { 23 } cm ^ { -2 } to N ( H ) \simeq 10 ^ { 21 } cm ^ { -2 } ( close to the the interstellar value ) .
The unabsorbed X-ray flux also decreased from F _ { x } =4.3 \times 10 ^ { -11 } erg cm ^ { -2 } s ^ { -1 } to F _ { x } \simeq 10 ^ { -12 } erg cm ^ { -2 } s ^ { -1 } .