We report the first detection of X-ray emission in a pre-planetary nebula , Hen 3-1475 .
Pre-planetary nebulae are rare objects in the short transition stage between the Asymptotic Giant Branch and planetary nebula evolutionary phases , and Hen 3-1475 , characterised by a remarkable S-shaped chain of optical knots , is one of the most noteworthy members of this class .
Observations with the Advanced CCD Imaging Spectrometer ( ACIS ) onboard the Chandra X-Ray observatory show the presence of compact emission coincident with the brightest optical knot in this bipolar object , which is displaced from the central star by 2 \farcs 7 along the polar axis .
Model fits to the X-ray spectrum indicate an X-ray temperature and luminosity , respectively , of ( 4.3 - 5.7 ) \times 10 ^ { 6 } K and ( 4 \pm 1.4 ) \times 10 ^ { 31 } ( D/5 kpc ) ^ { 2 } erg s ^ { -1 } , respectively .
Our 3 \sigma upper limit on the luminosity of compact X-ray emission from the central star in Hen 3-1475 is \sim 5 \times 10 ^ { 31 } 
( D/5 kpc ) ^ { 2 } erg s ^ { -1 } .
The detection of X-rays in Hen 3-1475 is consistent with models in which fast collimated post-AGB outflows are crucial to the shaping of planetary nebulae ; we discuss such models in the context of our observations .